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ii' " ""', ' ti "~" I " a If" The Law Enforcement'Standards Laboratory (lE$,L) of .the National Bureau of Standards .(Nas) ,c) furnishes technical support to the National InstitlJle of Law (Enforcement and Criminal JOstice o '" ,,(NILEOJ) program to strengtben law enforcement and criminal justice in the United ·States. LESL's fUnctlo,1t, is" to conduct research that will assist law enforcement and criminal justice Q' agencies in the, selec~ion and procuremehtoof quality) equipn'j(~nt. "

( " LESL' ,is: ,(1) Subjecting., existing equipment 'to Ilb~~atOrytesting and evaluation and (,2) confjucting . research .Ieading to the development of several series of documents, including I)." 0' nati"nal volul1tary equiptnenfstandards, user guides,and technical reports., " .' . ' j'; ThiS' ddCt6mehtls a law anforcel11entequipment guide developed by lESL under the sponsorship of NILECJ .. Additional gujdes as well as other docum£lhts are being issued under the '. LESL program in the areas of proiective equipment, communications equ'ipment, security ~ osystems, Weapdhs,emergencyequipment, investigative aids, vehi,cles and clothing. ' tp.c~"~",'il~' ~"'~~"~i~~ _O~"='~~'".c, , .. , __ ~,~ __ "~- ____ , __ -_-,.'c Technical comments find suggestions concerning this guiere are invited from all interested 'parties. l"hey may be addressed to the author or to the Law Enforcement &tandal'ds Laboratory, National Bureau of Standards, Washington, D.C. 202a4,:"

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C .'\.'; LJ Jacob.J. Diamond Ch/ef, Law Epforcerneflt Standards Laborstoly

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'INT:RODUCTION C' TVPIC'AL (i " • 'I. PHOTOGRAPHIC M r;±iVEH • f t ' wO ASSIGNMENTS

Virtually e~ery segment 'Of t~e law enforcement equipment reliability", factors that must a1lj'i$ 1

community makes extensive use of taken into account when selecting equipment. J;'~ . \J on a d'mily basis," pr~par~ng documentation, evi:' Matching,. equipment characteristics to specific I "dence, or visual aids for training and public assignments will help in the selection of the,: I education. Law enforcement photography,8s' a type that will Ptoduce tlie highest picture quality. . specialt}',probablY em:ompa~ees a' broader Judgment will t)8Ve to bie exercised and compro­ , range of specialized phofographicskills It-han mises may have to be made,.based upon the rel a \ any other recognized branch of the photog('aph m ative frequency qf use of each type of equip­ \ Ic profession. This guide briefly discusse~ thl3 ment, personnel skills, and personal preference. typical assignments that are encountered on a Only the individual who knows the requirements routine J;~sis and' reviews the types of pictures of the user can Judge these points properly. t. • () tha~ tfi~ photographer must obtain in eacll" instance. Those problems that are unique to In G field such'as law enforcement photography, specific assignments are identified, and some WhEli'9 widely diverse subjects are norma', the lusefulphotographjc techniques, are described. skill of the individual photographer is of maxi­ , ,~s, film, meters; lighting mum importance, and equipment canndJ be sub­ equipment, and accessories, are also disqussed, stituted for professional competency. The , with emphasis on the characteristics that are im­ ',' greate$t portion of the annual! cost of photo­ portant to law enforcement applications. graphic services, goes for' labor rather: than for equipment or materials. It woufd be sheer folly, The upsurge in popularity of photography therefore, handicap the photographer by I to Basic law enforcement photographic among. the general public na~freBulted in a floOd " forcing him use inferior equipment which to assignments are traditionally classified \) of new equiprr,tent, particularly in the 35 mm " wast~s his time and; talEmt. It. is hoped that this according to the crime or the object \\ I , field. The professional photographer has guide will assist in the logical selection pf photo­ photographed: homicide, burglary, break­ 1\ ing and entering, arson, sex crimes, etc.; 'i benefited greatly from the availability of this so­ graphic equipment which is best suited to the mug shots, fingerprints, physical evidence, phisti~ated equipment.., On the other hand,' the : job to be done. " documents, etc. .~ demand for specialized law enforcement equip­ i men~ is relatively "small, and some of the Jhe major manufacturers maintain" technical ',I popularly ad~~rti!ed equipment is not suitable $rafts to answer questions and assist in the ap­ for, taw enfo(Gtiiifent use. The individual makIng plication of their products to specmc uses. They \ '.,~ , ' ·Y, . •• the ~election must c~oose from the large vanety have published, a number of tlandbooks. which is commercially available. The final manuals, and technical bulletins that discuss choice Is otten a compromise. specific law enforcement applications, such as forensic and evidential photography, in depth. In The purpose of this guide is to assist those law addition, the monthly photographic magazines enforcement and procurement officials who are contain a great variety of photographic informa­ not \\technically trained in. photography in the se­ tion and can enable a police department to

lection and application of photographic equip­ ber'eme aware of new products as they are '\ ment Which will meet their needs. The basic i' int'oduced. The importance of keeping current operating principles of cameras, and with,. photographic technology cannot be over other equipment are described in order to make emphasized. A month never goes by without the . it easier' to discuss the considerations which introduction of a new , film, or affect their application to different photographic accessory; which may often be ideally suited to assignments. Emphasis is placed upon picture law enforcemer:lt application. quality, acquisition, and operating costs, and

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" graphed !n detail~ ~overage must be SUfficiently tion (suc~ a~ a broken store windo\i!) to very () thorough to leave no possibility for later require'" small objects under poor illumination and in "'I ments. wllie" were not anticipated at the time. inac~essible locati~ns (sf,lch as a bullet h0l.~, at. After a full set of.pictu(e's has been made,of the the scene of a shooting); .." .~/. ! • ,. I ,I victim as found,' it will often be' nec'essary to . t~ke ,add!tional, pictures of the body, wounds, In, many instartcas, the crime sc~me " . jI blood; stains underJhe body; or other additional will b~ the only record of physical evidence (or. Crime s2ene' a~d ~hy~'cai EYh~tence ,of the point of entrY, {oolmarks, ,trace evidence if evidence.onc;:e the body has been moved. ,. As' later use, such as damage to a .arge wall safe' such as cigarette butts, articles left at the scerie Photo9~raPhY :, i' with. an iir'iv~stigation of breaking and entering," that cannot be removed, from the property; in t such as fools, the condition of various rooms points of, entry and exit are important. other cases, it will be possible to fake items to, ( t and areas from were taken, finger­ f talj;E3:rJ:.~attj'~E!' ~cene of a crime" are (yhic~ ~rticles the laboratory for further examination ancLp~o.. . prints " or footprinfs :and the .a~,icles area The photographic conditions encountered "jn I essentiat t9,th,lE'f n,v,'e'Gti'~,!!1tion ~nd for later pro, s, Sa or tography. ,Weaponsal1cL tools' Can' Di:fstudied ~ I ·1I eUtiort'of those bharg~~ with theoffenseo The where found, and. the known or possible paths crime scene aSSignments. involve a wide range~/ u~ of exit. ., and ph.otdg~pfled to' display fingerprints,' or purpose of crim~ scene pictures is to show in from large exterior objects under good Ulur'nina- . uniqUe chara~teristics that will aid in the investi- deJaU the' objects, conditions, and relations I Photograpns taken at the scene of a crime in­ pr~sent at the tirtle the investig~til1g officers -',,) volving a victim, including drowning, are often ,_arrived. , r '-.,-j ttl , critical to determining whether the investigation Th~ "orlllal crime scene aSSignment ,,,wolves a concerns homicide, an accident, or suicide. I number of different pictures with WidE!ly different Pic:tures must be taken'': from all' sides of the requirements. t.iNerall ,Views are neeaed to body, and all wounds must be shown in detail. positively:, Identify the location" showing the Any weapons present must also be photo-

general and immed.,late surroundings and their ! , , relations to the crime sce:1e.Close-up pictures must be taken at progressively decreasing dlstanc:es and from different vieWs. The general ,~. .' photographic seq!Jence might go from street Scenes to the~ Ctwelling •. to the entry, to the V(f)v! • c room, the overall conditions of the roorn, and to any'vigtim irwofJed. Crime sc:ene' photography, () in general, involves relatively large areas and the pictures must have good detail and perspec­ tiye. Many of the pictures can be tat~el1 with existing'light; however, interior photo~raphy will most often require additional light. Artother type 'of crime scene photography is the recording of' a re-snactment of a crime. This requires a somewhat different approach. The pictures should be relatable and compatible with those taken at the' time of "the initial investigation of the crime. 'v . ;:" , With the exception of those pictures taken to fix

:. , the location of the investigation, all pictures made at the scene of a crime are potentially evi­ dence photographs. It is particularly important to obtain photographs of evidence that may be transitory in nature, such as footprints, tire', marks, or fingerprints.

When investigating a burglary or breaking and enterinQ, the pictures should include evidence 'or 2 () \ 3 I, ~ oc::::::::- ,L- " " : i7 \' W,_ L u p" L ! .4 J .". ) ] __----~----~~----~------~-----~ .. f--~~P c· 11:-­ --- _____~..-"V ..... ~-....-"-,-" ~,-;.,-.. --~" ,1[, .,"! / ", Iii ,]\.... , " li'll "".','r,' .I' " r5~'-:-:"----''''--~":~:''-'-"'~'~$~~"~ ~~L~~~»~,--.-c,"~,~~:~~~,:::~~,~;<:j-,~-,-~... -,"-.,_..,. ___.. ~~~'6!"." '" "I' ",,~)'';t; ""'::"" ,~~.~\""'.",;': I, "', . C::" !. .) (, :':, j :,~~~-'.-; ~~':- I>' I '.' I. " Q , i I! ~ r l~~ , ":' , f. gation~ Items can be examined and photo. trafficfat~lity . Or. injury.<:?en~raIView~ . are " grapti$d utlder other typesot iII~rnination such required t9 show the scen~ arid to'ic1pntify the as/nfrared o~ ultraviolet light, wriiCh may enable localitY. It !will be nElcessaryto shoW $s nearly <\ the detection' of such things!ds thealterationpt a$ possible each driver'S view of his ~ur"pund~ !-l an original ctleck sjgna(~r4:' The "photo~aphy iri~s, priotto'theaccident, particularl~,," his i\ pbssible '~Iew of the approach the other \1 studio will also be used to make reqJ)fds of of i.! property; such as' fl'. stolen !~.aio,.,;.J,}iC:ked" up vehicle;·· what \-i6W each driver ha~ of, the;, other at the pdint 'of impact; genera( views of the , during: a"pawn ,shop Investigatio(l. ,//, " .,. I , >' <.J' j~- vehicles involved in, relation to their surround­ 1'.' (: 'j Photographs. of se~cri~e}~ctims are still ings; a c!bse,up of the' damagect yehicles'"and, the locatibns of. thfose injured orf,'killed; vi~Ns of ,anOther type of eVldentl~V /photography, and " , '" i' . . " ." , 'i'.' -, require the full coop~rt1tiq'i1 of the victim. dirt dislo~ged from the undersiqe, of vehicles, .in,- Pictures may be .neC~$$ary ~o sUbstantiate'the dicating location of c9l1ision; views of tirs or skid fact that sexual ,assault ~ was .' committed~ marks .. or other, e~idence ot preventive (.:.:' Evidence of resistsnce to the'\sttack in the form measures or lack" of them .. Any record tl~at would .indicate "a mechanical failure of either of wounds, bruises, scratch'es, etc;, are of " ~ " \ _/ ~J \ important. ' 'tC, II special importance. . vehicl~)s"tiiso !? /1 I\~.'L ' 0" • l Tite skid marks reguire' tWo' views:., one ri . •Traffic ac61dent pictures form a complete docu~ or I menfatidn of an automobile accident involving a looking in the direction ol'"travel from as high an t .Y . /; ,.

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.' ~'r_, elevation . as feasible, to ,indioate evagive"'> best be. taken from a considerable distance. , maneuy-ersmad~t:!y ttle driver; the second view ,chboSil':l9 the camElra viewpoint ,.carefully. to atA.~9ht; ,angles to the direction Qf travel, show what is wanted. A long or telephoto l enabling .the length of the -tire. marks to be lens. should be used. Crowd views require

determined. ,/,'Such marks must also . be working in close, at the scene of the aetion,. i\ , measured. ' making it a d;tficult job forons person to cover." After the fire, acamplete record at the. pOint " (: Arson photography represents one of the more where the fire start~d, its direction 6f travel, the difficult assignments. It requires careful damage, and any evidence of items that were coverage from several viewpoints, which are not used'in starting or spreading the flames must be compatible. An overall general' view of the obtaine(f~ The required photographic techniques sgene Of the fire, showing sr,noke formation, are familiar to the experienced' photog~~pher. In co!or of c'smoke and flame,location of initial the photography of fire-blackened areas, both fl~mes and direction and speed of spreading, is lI~hting and exposure must be modified to meet i~"ilportant. At the §,~me time, pictures ot' the ti'io conditions found~ Normal exposure, using I! crowd of· spectatr.ifs-s~{1?uld be obtainecHor the flat lighting of fire-blacken~d walls, produces possibie identific~\tion of arSl,)n "repeaters" who very poor picture quality. Lighting to. emphasize ,.,f'may be present." The first set of pictures Ilcan the texture of the burned surfaces' should be ,:;:" " 4

• [ iN . ~'.' ,; \~;\""', " IL+~., , ""'P ...:{. . '1 . . ~'I'" " . b" " OWl' ,a;~ " 7···. '., 'ell),," . , oe '.' ?', .. \;' '."'.' .. ,'" """~_""'-"'.. ::"'.".. """";""""'" ".:'. .. ,".. '. """""c, ..",,',," ...... '.. ,~. ¢'.\. ,;,,:\~\ "',. " .' '\'\\ \ '.' '. "'--'-'1:- . ~---"~ .. " --~" -+~~",S~0~,.. ; ~~ \; '~';-~ -:.. \f'--~'- '¢ ,;:.:~ ~, k~t ';;'~."., "'l!.,,- ~ .... _ '\ ' Q .~ , • '., '...... ,., ''<,':'",Q;, "~, '. '<"'\<;:' I ' " ~ necessitate p\inting frOiJ1 apositi.ve tra~;pa;;~~' ril~c~~l1otQg;aPhY. While 'a.II' documept wor~ "'-r"". cy made' from. the lief}ati\te; instead of directly >wilt fall into"'eQsor the C)iher' of tbese,two "ftolll Qthe negatlv~. ,... " '. cate-9.9!ieS;"notall'hlacro.Photography in .the 'Iaw,~ ~ " Q: " " enforcemenffieldisdocumeilt"pilologtaphy.· ~~::' Sun'ellj,~!lc!~ Pho. tog. raphy>~" ;"~'~ ". ' '.. .' . :" ~'''' c\ . " .... --'" (.,. ~'.rnajor 'document·~sl:;ignm~nt··may be the' " '<;:. SUrVeiliance'photograpnYisairected,tow~i:cf the -". . si!'"plecopying of persa~nel identification photo- preparation of s. pflotogra:$hic record of sllspect graph~ solhatprints are a,vailabl(tt(l aU the in- . ~ct!o.ns.T~~ surveill~nce ";Iay~(ntl:!l around an ve~tigators. Oepefrtments withe '~rge')~I,ume:of . IndiVIdual or around a,locatlpn. In the case of an t' investigat~o~"wilt 'require .~standardized~~RY "c. <", ind,ividusl,lhere is intere$t iheverythi~g'hedoes\·set~up whicn can repi'odl.i~e, rapidly·;"and elf.,-, ·~nd everywhere he _goe~-( The" surveillance cieQlly, dC)cuments, photographs and' other '\->~ operator must be' ·sufficiently'''''' close to' the <' paper, originals with sizes of 28x 36 crri .... ,.~ suspect to record his 10cation"snd"l1is actions. .' {11 x and .larger. The . ~ ~,,_ .1 14 i~) pr()per.~?pYing t,~ 'This requires a maximumofingenuiiji, the .. "camer~_:.o~11I :provlde,or€ductt~! 'same SIZ~ or t,. "'c~r~rul s~lection Of. sqLiipment,~ adequateY=~'-':~iilafge~,c~Ples, . fro~ one-fl~h orJ)ne~~~.nth ~J ; 'msrpower, and much experience (and luck). In ,. ac:tual.slz~ ~p to five orm,ore times actual s~,z~.

' ~ :,~, -~"::';~~"-~")';~:&':~f-~-~.-;r.-.. ~~~z~'~k~*~~~=;~~~=~~~~~~~~: \:0 !!'aliy cases, t~e task is, impossible or impr8,cti-'" sizes forsl,lc~. ,~a~ras tend to be Do. " i 'FI,ng'efprfnt$ >, ,.'. ~ cal,~nd ev~n If pictures are obtained, they may. much la~g~r than normal, frequently ~O x25 cm .1 . :/AF. ,:; . ' o,~': not be~()f direct use' as' evidence. k (e~ 10. In) a~~ lar9<~~· A large amq~nt of d9~~- il , ijfngerprint 'phRtography Js a specialty, and the ,''0 " '" • '--t, '/ ment work wlll"be .at a ons!!tQ::one ratio. . """ I! " , pingerprint expert will bavs a special set of tech- . '" In the case' of a.location,surveillance, there i is .. ""'" . () -~'->:~~"'-.. ~---,:.> "'\,~, '. ",·hiquas •.• !Q.e ,g(j)neral law,':~nforcem§nt,phQtogra- .' (,., interest not only in w~at Juippens at the loca.. Fortne .smaller department, where ,a 'process t"" pher wiWl18ve moreJ!lT1ited contact with finger.; ,nly ,m~thods:(a) (lusting. with various colpred photographer. In practice, ideal conditions are "<, '~"'!lathed 6f, reliably .sh~iNin~ .f~~:aJ. ?hara~teris- \il~ 'co pdWd~s that sticki! to "mttprints, increasing their the exception and one must· make' the best. of tics, and a. good one will enable .~~~ ·!,~vestlgator cd'ntrast against th~ surfaces on~ which they are whatever ~onpitions are found, and select equip­ otwitn4:)s$ to. recogniz,e(~f! suspeett;Wdli.9ttt. At found; (b) "lifting"!~the powdered prints with an ment to suit thS'conditions. leas;t two views of each subject are requlrect f~f adhesive-backed ~Iastic tape and transferring "an identification series to" be complete: a front' ,Jhem toa rrioresuitable background; (c) iIIumina- " The Item$.most.often Iboked1OPi~OJV@illance ":- "', - ,r - !l.." _ '_~,,~, view a.rd Itt .~ide vjew. The identification phot~~ 'ting·the prinisWjttH.lltraWi{)letlight to make them ,o"<'J!tt.e.tos are recbgl1!zableor identi'fiable faces> graph 'is most often a close-up of the head and fiuoresce;(d) fUh1lngtije prints with e~(lljce!,",""'"'''''''' The't:':.l,,~ubieic,t" dist~~ce is,,generally large shQ.~lders, emen,ding; dow;~ to .the ch~st only far 'vapors; such as iQdine.,-,\, ...., ",.. " com'~~-to the subject size,~Onasrthesecon­ t enough to show the Identification or file number. ,,, .,. ditions,'n-eg1'1t~ye size is ofmfjch 'jess impor­ · The side view is most' important for 'absolute Fingerprints may be pl1\otographed 'with (a) a· '" tance ~han in olh~! photographic work;r,Wtt.~t· is, identification; it prov,jdesmarty. more ~Jements special fingerprint cam\~ra, whlch isa self-" of importance is, image size. and this-'is v for. positive" id~ntification than "sf:iy other view. .~. contained .unit providing t1jxeQ magnification and det~.rmjned by lens focal. lenglh and subject· To theurltrainect eye, how"6ver, the front view is integr~J lighting; (i:») Withl\ a pte~s~type camera distance rather th~n negative size. o more recognizable; it is widely used for ..display adaptstlfor fingerprint pt:~('jtography"l;>y means to witnesses ..'. Some pOlice departmentsal~o of special attaChments; or (c) with 20y other photograph a full length front ""iew of the iypeof camera which .is ~uitable for cto~e-up ,.,Docume~t Photography .

· standing suspect and occasionally a three- pt)otography. ~'" .\ quarter view from each ~jde. In all cases, tile '\. Document photography, from a photographic ,~ <' pictures should be Ijghted 'for maximLlm detail. In printing fingerprints for co,urt presentation, . standpoint, Is th~ simplest of all assigrlments. · Th9,9i.2ture should, include any unique \features, they shOUld always be printed So that the ridges All of the work is coo!ainsd in two re!ativ~ly'we" such as sears. birttil1'1arks, etc .• that would aid in are dark.and the grooves are light. This may defined photo,graphic areas: copying" and l~ ." ,(".' • \\ .6

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(J thesecol'lditlOnSf,themediUmformat',camera be used. This is,th~,area whereautorriatic and 6 )( 6 cm(2 114 X2<114.10) Or' ,10 x1 ~.~cm .. instan,t "processirtg', cameras (Polaroid and the J::)'(4:x."sin) is little more trouble"'to,~ 4se than'~newKoa~k equipment) '~ave Jheir greatest "\ ' 'f3mali AQJmat ,camera, The phofbgraphs.J:nade' . utility,..",' " '" '.WJth. t~e"'fargerformat camera~ilJ oft~n titl','of:. '.' ,pett.erquaUty,.pa.rt.icIJ.larIY\ifa blqlw-uP .. of a small "the purpose of ~ ·docllm,en~ation pict~re ',sib .::., portion bfanegative is required. \\ ,.' a(i~",.tQ theinformatj,on which the investigator \. . '" . ... ) ,'" "reco~ds tCkptn down dlatail~ that might be Md~.lon Rlctur,Photography. rem~~pered 'irnpert~ctly and to. preserve infor~ , c ,< ,'" ,;~~,,~= C' "; . ==~;-';O.'~.""~c",,,=.,~~, 0,.., ", ., mati6nWht h is diftiCUit,or.~ery tim~ consuming ., 'Motion ~Icture"photography. has prol)ab~~~Q~.t·t~ record properly ,by .otnerrneans. These used insu~eUrance and an~oninvestigat~Qns-"-1''',<::~6tosal'e nQt'il))~nd~~t ~~~"ig~!lc§. ()t;:assub­ moteth.lin :,"'ot. ~er law., en~orcem. Et?,tactivities. I, sli~a~or formal; photography~ they.~~y.~e.,~, o.f, ,,' Much ,detail can' .be seen In a motl0ftPlcture,.. relatlvely"'row quality and have InsuffiCient detail '. ~, ., 'such as, .asurveillanQ~ photograph of a suspaQt", II to allow 'enl~~nt. They are ,intended to :SI,JP- .. HqweVt':!r, a still picture mad~hJrQma single 1';.~~ment the notmal"'p~.ptograptls and investiga~ frafn~may be useless"for 'ide'1tif~tion.ln part. \tor$-'nQtes. They ~re particularly valua,ble in sitlt­ .~~i~ b~a~se the Subject is mg~e~.g,ahd the.in~ \ations in which'i~i~ impossibl~,ir:npractical, or "",-, There is such a Wide range of camera type~ available that the pOlice photo­ dlv/dual frames have too long an 'exposure to \'. top costly to aisslgn aregufar photographer to grapher,,~u~t define the needs, of his assign­ stop th_e sul)ject's ,rmot!oo., ,It isn"t necessary. to \ make a thorough photographip record. The ment in bi'q,er to choose the camera that stop motlohf~ra motion' 'picture~ln part, the, 'instsni,:process photograph !s of~articular value, would be mo's't-!:teipful. '! , ,~ .- ",\", l)ettE)[,apparenttjua!LtY of the motion picture i.s" ,~~ an'i!"terim record,that the firsf pfficer on the '::;'> due !~o ·th~Jnherent ability of t/::le eye to take;El·~:~<;ana can get and uSe to conv~y Information detail ~ut oltm~l~~arne and add details.print$ can be madea~d i~istributaa. " i ' <>\1 t i 'i! ·:i J' ,; 11 11 c • II c"f! ~.;

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II· ~fi!!m=t~gG;orrles more. \critical.lt is, apparent, then, adjusted until they coinCide and become one. At ~~\MERAS that the camera mu~t be' considered as one part " . this point, the subject distance can be read off a of the total photographic sy~tem. 'The trade~off scale,!f desired, but the camera lems has simul- ;, ~=,.~~~.""""""'~~~' 1/ factors relative to film' size include 1) the ideal taneously be~n adjusted to the proper focus. In '11 ...... ·•· .. ·•· .·.·.·9·· ...... 44RB.' ...... ~~ ~Qj ··Em~ ~i·~i·.. ~~~i~m ~ ml ~'~:>:~··rt..... '.. dtfE ,""* Hr" -<=- i size, from the standpOint' of picture quality, . for the split"Jmage) type of rangefinder,adjacent the particular task, 2) the . lowest material cost, If --o-.~:;~ '1 areas of the image ate moved with respect 'to obtained by the use of a small neglitive size and each other until a line which is cOntinuous in the Gi!neral approximatelY'3 m(1 0 ft), ,and at very long Conslder.lIons only one size for all tasks aod 3) efficienoy iO.~, subject becomes continuous across the image . "" ' . .... distances when a is ljsed. While manpoWer .use, which Suggests the smallest 1 _.. __ ,:c· ' ' ". .. ..> .... '.'.. "'j,O h'- h"" a n'um'be" r of' .c. arne" ra designs have incorporated dividing line in the eyepiece. The choice The convenience and efficiencYI'wlt,·lw. Ic~_any possible number of different types and a film ",type of p~otographic·as$ignment can'be acco~~'- '. .adjustments ,to minim!zoe the problem ~f ··view between rangefinder type$ is primarily a matter size that requires the least time and;,lowest level of personal preference. plisf1edis larQsly diq,tated, by .the camera that IS flnder

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4 U . " 1culty'with this type of viewflilder than those'who currently available; however. it 'now appears that· ,( ~ ,~ dd not at least one manufactl:uer will start to make the )\ " various lenses. Remember, no view­ pUshed using only the ground glass scteen. For press cam~ra in the near future. finde~ will enable the photographer to observC9 The rangefinder. camera is most suitable where inside studio Work, it is essential, and Jt can be the effects of view' camera adjustments'upon used in the field as well. The a small, quiet camera is r~quired. In the 35 mm The is essentially .~simpl~: direct' the image. (i:;/ . '" size, where the ch(jice is between the rangefind­ view camera with a few added features. many provides a. wide range of adjU~tmentsfor changing the relative location an'gular er. Ell1d the single lens reflex types, the, rangefind- of which may be separately purchased options. Press cameras have been used for every type /~rid positiori of the lens with respectrfo the film. The o erls major advantageis"its ability to determine . Press. cameras provide for direct' viewing of tha enforcement photography and are an ··~"'cf"."aw distance between the IEjlns~\rjd the' film can be focus under poor light conditions more easily subject image on a ground glass. in addition to ide~\\ choice for.. many assig.n":Jents. providing adjusted over a wide ra~ge, .from a: small 1 than the single lens reflex. It also has· a much providing arl~optical viewer. For general police WIth a mlmlnum amount of m~fJlriurn.ver~§tl!lty fraction to three times thEt/focal I~ngth of the lOWer, noise I~vel than an equivalent single lens use, the coupled rangefinder is the mostimpor­ equipment. The level of skill required' speci~! to . View cameras. are essentially reflex and. in general, is a lighter and signifi­ tant option. Itshould'be noted that many or the realize "'the ultimate potential of the press cam­ t large-negative cameras; 20 x 25 cm ,(6 x 10 in) cantlY.smalier camera. Thus it lends itself to situ­ older press cameras did not couple the range­ era is relatively high. The basic methods of the standard size. Recently, a size of ations where the camera shoulc! be,as incon­ finder 'to the focusing ,system of the camera. operating the press cameras tend to encourage i~) ~egative 10 x 12.5 cm (4 x 5 in) has gained popularity, spicuousas possible for a given film size. Some press cameras also provide interchange­ ! the operator to utilize ~more care!!1setting up and view cameras using a negative size of Parallax is a problem with the rarigefinder cam­ able cams t9 enable the rangefinder to automat­ 1 than is usual with, an' automatic camera .. The r 6 x 8cm (2 1/4 x 3 1/4 in) are available. era and it is not the best choice for any task in­ ically focus lenses of different focal· Jengths. \ result is fewer but more carefully planned pic­ , 'a,:, Volving subjects' at distances closer than 2.5 to. tures. The skilled!1 photographer can use .the Because of its large negative and ground glass 3.5 m (8 to 12 ft), or for use with long focus or Slide and swing adjustments are the second press camera on almost any aSSignment most important option. These adjustments,'built } viewing screen, the view camera requires the telephoto lenses. With extremely wide angle ." into tl1e front andlor back of the camera, allow least skill to visualize the finished print; lenses, the parallax e1fedt becomes very small 'Fhe press camera is much Simpler mechanically however, of all cameras used for law enforce­ and may not be (such lenses general­ the PQsition of the lens with respect to the film o noticeab!~. than many other camer6l,s, resulting in higher reli­ ment photography, it requires the highest level Iyr~quire accessory view 1indert~). to be changed for distortion controt When the ability ana easier repair. It is versatile, and the . ,,' I of skill to set up ,arid adjust.' ground glass screen is used, a or other 1., large negative provides a safety factor inal! op­ The initial cost of , . camera stand is mandatory. This' en~bles the a erations from exposure to final printing. The view camera is the only camera that has r press camera to be used for many of the assuming comparable picture size, , However, it is large, weighs considerably more been specifically, deSigned to eliminate the r lens quality and optional features, will be signifi. functions of a studio view camera. Recognize, I than smaller cameras and is slow to operate. shape. distortion that is present in 'nost photo­ r cantly less, than that of othElr cameras such as however, that the greater the number.of 'adjust­ Since it lacks a built-in exposure meter,'ihe pho- i graphs. It als~ provides highly derailed ultra­ the ,single lens reflek or twin lens raflex. There ments that are provid~d, the' rn9re the accuracy . tographer must use a separate one. While its closeup pictures; for example, a ten-times mag­ and ,reliallflity of.' the coupled rangefinder is is one major exception to this g~nerality-the size and operating procedures make it nification of Ii thumbprint requires an image·size top quality canleras are provided with a great ~.' jeopardized. For the law enforcement" depart­ unsuitable for some aSSignments, such as sur­ of 20 x 25 cm (8 x 10 in). It is, likewise .ment with only occasional need for a "studio many featur.es which are not found in t!le great veillanc~, the press camera is an excellent cam- , adaptable for use in the photography,· of tool majority of cameras; are view camera, the press camera with full.adjust­ ~~gefinder t~eir1>fices era for all:'around use." marks, morgue shots and forcible entry records. ment capability is an excellent choice. ,~ comparable to those of _~~ batt~r quality single II lens reflex camera~J.4~~ , , The press camera is strictly a professional cam­ The major features of all view cameras are quite Some press cameras are also provided with a era. Because of its limited market, the initial similar in' principle, differing mainly in their Pr~sseamera$ revolving or reversibl,~ back, which allo~s either cost of the basic camera with one lens is high . precision of construction, the care with Which horizontal or vertical pictures to b~ taken compared to either the s)ngle lens reflex or the ,jOints are fitted (this determines the overall - '" " Tha press camera, coupled with photoflash or e­ without turning the camera on its side. A rangefinder .cam(i3ra, as is the cost of accesso­ lectronic flash sUpplementary lighting equip­ revolving back allows the film to be rotated ries. This cost, however. will teod to be offset by ment, has been the starting camera and "work­ throu'gl:l afiY desired angle, while the. reversible long 'operating life and ovsrall reliability. horse" of tile photographic units of m~ny lawen­ back H~'s two fixed positions: vertical and hori­ Similarly, the large negative size will result in a forcement agencies. It uses rather zontal. EIJher is cpnvenient, and both increase relatively high cQst per picture .. taken; however, /1' than , although film pack adapters, roll­ the utility of swings, tilts. and other ~djustments. this will tend to be offset by the greater percent­ film holders (anti. 'P~laroid .adapters) are readily age of good and usable pictures !haL~iII be available. The size range is from 6)( 8 cm Almost all press cameras prQvide one viewfind­ produced. IJf"'~'\. (2 1/4 x 3 1/4 in)' up to 10x 12.5 cm er in addition to a grou'nd glass. The separate " / \~, ,. (4 x 5· in), the most common siie. Th,e increas­ optical finder can be adjusted to match a full Studio Vlew··Cameras ingpopularity of the smaller format cameras range of lens focal lengt~$, or a few specific pfompted all manufacturers, to discpntinue lenses. Some cameras combine the viewfinder The studio view camera,1J9rmally referred to as making the press camera ,several years ago. with t,he coupled rangefinder. This combined· simply a "view c;amera," is the traditional cam­ COnsequently, only used press cameras are vieWfinder/rangefinder can be adjusted for era '~y wpich·the·· commercial photographer is known. All focusing an~l:tomposition is accom- '12 l;'l 1.3 "

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, ~,. limited. by the number of holders carried unless ribldity·:'ot the vcamei'S, 'particulerly in larger can be. easily . remove~' an~ repla~ed ~ithout a ,changing' bag is used. The camera is large in possible, however, to set t~e to the ex­ sizes), the ease with which adjustments"can be danger 9f moving the camera wh"~ tryl~~ to 'size and heavy compared to smaller film size posure setti.rg to Observ(il the depth offield. made, and the ,independence of adjustments change Ii holder against a heavy tenslo~ spring. clflmeras. Its ability to ~~ke short exposures is Most SLR cameras of current manufacture arso from each other. , , incorporate some type of bUilt-Ii' exposure Other available features include "fresnel" type greatly limited by the long focal length lenses used (which require for control, permit the Lise of interchangeable Vi~w camera adjustme~ts are. ba~tca"y sWi~gs field Ifmses behind the viewing screen~ to, reasonable ) ilndby the large lenses, and all provide either plug sockets or (rbtationabout a vertIcal axiS). tilts (r?tatlon brighten up the viewed image, in. t~ecorner~~ of shutters they require (which generally limit the "hot-shoes," or both, for attaching either about a horizontal axis), and slides (hOrizontal the screen; sectjon~1 ,~o Increase the ''Shortest exposure to 1/50 of a second or photoflash or electronic flash units. or{ vertical displacement). Adjustments are more total lens ext~nsion for .~~rem.~) enlargeme~ts longer). Any operation in which a large voillme e~sUy and quickly made iJ the. back(fil~ holder) of ,fingerprints and small Objects; revolving of diversified work is being done will, require at swings and tilts are on PIvot hnes that. Interse?t backs allowing' the film to be set at any angle I The film sIze of SLR cameras is baSically limited 1 leasf oos viewcam6ra to be available for the 1 at ithe center of the viewing screens~rfa~e. ThIS (all view cameras have a reversible. back for hor­ to 35 mm, with more than 50 models available,. ~ accurate portrayal of crime scenes, accidents prbdl~ces the minimum lateral, longItudinal, or .. izontal or vertical pictures); r~uclng ~acks on and 120 roJI film, with approximately 10 models and some physical evidence. . focus shift of the film with respect to the lens the larger cameras to take sma~ler slz.ene~a­ to choose from. Most of the 120 roll film cam­ tives' reflex viewers for convenlenpe In uSing eras produce a 6 x 6 em (2 1/4 x 2 1/4 in) when'the back is adjusted, ,and minimizes the As with the press camera, the initial cost of a the on a vertical copy stand for. the nerlative; however. a negative size of 6 x 8 cm amou,,~ of compensating lens adjustment that ~amera modern precision view camera is higher than must·bemade. In some cameras, the back routine copying of documents and for macrop~o­ (2 1/4 x 3 114 in) is available, and two manu­ the cost of precision 35 mm cameras. View facturers recently introdUced cameras that pivots about its bottom. e~ge instead of at the tography; and a wide variety of ac?essory film camera lenses are always sold independently of holders for both sheet and roll film and for produce a negative size of 4.5 x 6 cm center of the film, causing a very large change the camera. View cameras have extended in focus as the back is tilted. Similarly, the lens instant-processing film. (1 5/8 x 2 1/4 in). service! \ lives, with 30 years of use not tilts and swings should be abOUt axes that uncommon. The cost of operation will be higher intersect the lens axis at about the surface of Two basic types of view camera construction per shot than for any other type of camera; Some older SLR cameras have exposure () the lensboard. This minimizes change in camera are found. The monorail has all parts mounted however, this is offset by the quality of the pic­ meters that are integral to the camera but not direction to maintain the same view as the lens.. on a single tubular metal rail,. which m~y be tures that are produced. coupled, requiring that the and ap­ r is adjusted." , rectangular, triangular or of other non-Circular ~. ' erture be set .manoally after the correct expo- ( I cross section, to prevent retation of the front or . sure has been computed from the meter A good, view camera will "Click. stop's" or Single Lens Reflex Cameras I h.~ve back standards around the bed. Traditional view reading. Most cameras of current manufacture some other means of poSItively settIng ~II the cameras, which were largely of wooden 0 con­ use through-the-Iens meter systems that are adjustments at ,the ~ero or centered position. struction, used a flat bed with two parallel metal The major characteristic of the Single lens reflex coupled to the shutter and aperture. SLR tracks to guide t~e back and the front standard .. camera (SLR) is a deSign that eliminates view­ Sliding and rising-falling fronts and backs should. systems measure the light from the scene in Both types of construction are still found. Th? finder parallax. An internal mirror reflects the . several different ways. Some systems measure be designed" so that their adjustments ~nd locks camera should be carefully checked to see. If image from the camera lens to a viewing screen aI/ of the light entering the lens, some average are completely separate f~0!1l the sWI~gsand the total assembly rigidly locates the lens With which enables the operator to focus and all of the light with emphasis on the central area tilts, to prevent a ~hange In one adjustment respect to the film when the ?amera is 10Ck,~d. compose the image exactly as it will appear on of the image, others use a' spot meter, and from affectirig others. a" ':'(his is particularly important In the larger ir,ze the film. When the exposure button is pressed, few otter a choice of meter operation. While the the mirror swings auf of the way so that the In a standard the "plane of sharp cameras. All view cameras should hav~ a majori~! of exposure systems require that the camera~ image is formed on the plane of the film. In focus" is always parallel to the film, at right .~liding base for attachm~nt to the tripo~! so that oper~tot adjust either the aperture or shutter .. the complete camera can be balanced over the older cameras, and ina few current models with I!J .' speEJd tq' set the correct exposure, there are an~!es to the optical axis of the c~mera, and ~t film sizes larger than 35 mm, once the mirror is the distance fl'om the lens for whIch the lens IS center ofthe support . cameras' which provide fully automatic expo­ tripped for exposure, viewing is "blac~ed-out" the view camera, tho plane of sharp sure. All of these systems (10 a good job, but focused,l~ until the camera mechanism is wound to" focus can b~,tilted at an angle with respect to The view camera has. several major disadvan­ the operator must recognizett!at the SLR may tages for some law enforcement aSSignments. It advance the film for the next exposure. The indicate incorrect: exposures '\l/nder . certain the camera's axis and rotated around this axis majority of SLR cameras incorporate an instant­ ., as desired. As general. rule, the sw,ings and must be used on a tripod, since the camera Iightit'ig conditions, such as a small' dark object a 'return mirror which automatically returns to the tilts of the of the view camera are. for must be fixed during adjustment. Setting-up to that is back-lighted, or a small brightly lighted viewing position as soon 0 as the shutter has take a picture requires more time than with object silhouetted against a dark background; thea purpose of co~rrecting distc)rtion an.d thos~ completed the exposure. on the lens holder are for the purpose. of mont other types of camera~ It does not lend The operator aware of the problem can easily correct for such lighting conditions. It should keeping the ~esirecipart of the subject in sharp itself to situations requiting rapid changes of lo­ Virtually a/l SLR cameras incorporate lenses focus. . They .may' be used together ,(;)r cation or viewpoint. It most often uses indi~idual whose can be preset. The camera is also be noted that many SLR camera exposure film· holders which must be loaded In a systems are very sensitive to light entering "- . . Independently.. focused at maximum aperture, and during expo­ I or light-proof changing bag. Th~. total sure the lens aperture is automatically stopped through the viewing r!3yepiece. Photograp,hers A modern view camera. will have.a tension number of pictures that can be made ~Iiho~t down to that preset for correct exposure. It is who wear eye-glasses must be constantly alart release 011 the spring back so that film holders returning to the darkroom for re-Ioadlng IS to prevent inaccurate exposure readings .

14 15

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.,,: ... -,:. posure (1, second or more) to minimize the Most TLR cameras are manufactured in the Rubber eye cups with correcting lenses are extension tubes, be sure to' determine whether 120 effect of mirror yibration on the picture. Mirror roll film size. The TLR camera is widely used in avaiiable to'remedy this problem. the automatic ~perture features .of the lens vibration may be more evident on a light tripod making parsonal identification. photos. An electri­ couple directly to the cam'i!ra exposure control. ,i with some cameras at shutter speeds between cally operated TLR, using 70 mm' film in 100- Many, but not all, of the SLR cameras offer inter­ Some of the 120 roll film size SLA cameras use 1/250 and 1115 second than if the camera is .. foot rolls, has proyen very useful in departments ;f changeable viewing screens and' eyepieces. a between-the-Iens shutter, and each accessory hand-held. The noise produced by the focal­ where a large volume of such work is done. Offen, the camera csn be ordered with a non­ lens must also have its own shutter. In general, plane shutter and mirror of, a SLR is much Using machine processing methods ( standard screen if desired. The available types the range of accessories f9r the louder than that produced by' a betwe-en-the~ Versall1at), conSistently high quality negatives range from the plaingroulJd glass (commonly SLA camera is more limited;, than that· of the lens shutter. The noise may be a serious disad;' called matte), through various types of micro­ 35 mm camera. {) can be obtained in large numbers with a mini­ 1 prisms designed: for, specific focal length vantage in covert surveillance photography. mum of labor. \\ ranges, to clear screens for aerial image The SLR camera requires a minimum of .1 focusing. Some are available with a split prism operator. skill to produce high quality. pictures. Quality 35 mm SLR cameras can be purchased Several TLR cameras incorporate built-in expo'· I in the center of the field. The standard matte These cameras are necessarily complex in both for $300, with an automatic lens of normal focal sure meters that are coupled to the shutter and ground glass is prp,bably the best choice for all­ ,mechanical and electrical construction length and built-in exposure control. Th'e 120 aperture, and adapters are available wbi9o~._. round use and fq!/ the best visualization, of the:. however, and are more .prone to malfunction SLR camera, however, is much mare expansive. allow the use of 35 mrn film or sheet film. Only'-­ final picture. The micro-prism is, a petlbled than are the simpler cameras. Similarly, when In general, the prices of SLR cameras are' a limited number of attachments or interchange­ surface on which the image appears to break they do malfunction. repair can be expected to exceeded only by' the price of top quality view able lenses is avail~ble. Eye-level finders ~re up and disappear unle'ss sharply focused. When be more expensive than with a rangefinder or cameras. also manufactured; these allow the direction of

I,']~ focus~d, the image is seen; when the image is press camera. Also, mirror vibration is a sight to be parallel to the camera axis rather not sharp; the pebbles or prisms are seen.' This problem that is peculiar to the SLR camera, If Twin Lens Reflex· Cameras than at right angles to it, and some" choice of $creen ,is good for use in poor lighting'condi­ the camera is not firmly supported, the vibration viewing screen style is provided. tions. The split prism is also good for very wh~~ the mirror R!0ves from the viewing The twin' lens reflex camera (TLR) had preCise' focusing and for focusing in poor light. position may be sufficient to blur the picture. ,widespread popularity, particularly in the period Ths level of skill required to opsrate a TLR is on The viewing screens normally have field lenses The .extent of the problem varies depending i before a large 'selection of SL!1 cameras a par with that of the rangefinder camera. The ,to provi~e a bright picture from corner to corner' upon the design of the camera. High quality became available. The· TLR has two objective large viewfinder is sri! advantage to many this is standard in most SLR cameras. ' SLR cameras have a control to manually lock I lenses mounted one above the other. The top operators. The TLR camera does, however, the mirror in the "up" position when the camera lens, by means of a fixed frcmt-~urface mirror, suffer from parallax. Since the TLR cflmsra is The ability to use a variety of different lenses' is is used with an unusually long focal length lens r reflects the image to a hor;2ontal ground glass not complex mechanic:ally, it is a reliable cam.i' a major advantage of the SLA camera. Both with a microscope, or for very long exposurEls: I viewing and focusing screen at the top of' the~; era and repair costs are relatively low. bayonet and screw-in mounts are used to In this position, the camera is "blind" and the camera. The image is right side up, but reversed attach the lens to the camera, with most of the imaye cannot be seen. If the, camera must be from left to right. The lower lens is the picture . The initial cost of a /rL!1 camera with a singlell higher quality cameras using the bayonet used on a light tripod, use either a very short ex­ taking lens and has a between-the-Iens shutter set of lenses will be, about the same as for the mount When selecting accessory lenses or posure (1/250 second or less) or a very long ex- and iris diaphragm. The twin lenses are carefully SLR ofthe same filr size. While there are il1r},i­ matched for focal length. They are mounted on viduals who prefer Ito use a TlR camera, it is a common plate and are focused by moving not normally considered to be a top choice for them together as a unit. The viewing lens has law enforcement photography.

f) no adjustable aperture or shutter, and is normally supplied with a larger aperture to increass focusing accuracy' and image Motion Picture Cameras ,,:, brl.ghtness. Unlike the SLR, the operator can see the image at all times, even during expo­ The motion picture camera is essentially a sures. motor driven still picture camera. The mechanism automatically takes pictures and advances the film at the rate of eixteen or more pictures per second. Most cameras operate on

I a cycle where one picture is taken for every ~. revolution of the motor drive . During half of this revolution, the film is stationary and e~posed to light; during the other half revolution~ the shutter is closed and the film is transported out of the picture aperture and replaced with a fresh section.

17

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Four sizes of film are commonly usscffof motioQ, .. \ ': Two major uses for movies In law enforcement Polal~oid and'Eastman Kodak manufactUre color . '" picture work: 35, 16, 8, and Super-8 mm. Thirty· 'photography are surveillance_phdipgraphy and five millimeter (the same size as used in 35 mm films: that do not use a separate paper negative. . \ in recording tests and bGhavior in ·'diWihg. while mken with those films reqUire sevetal still cameras), is u$,~d exclusively for Picturel~' under. the influenced 'Of alcohol" (DWUTIA) .... minutastO tully develop' the image~ comm$rcial movies for theatre showing. Sixteen , 1'\\ r \"\1. Y ' arrests. Where surveillance is from:.G"fixed loca­ ,~~' millimeters has been the standard size 'for ail '11 I'll \~ \' tion and the larger size of the 16 mm eqliipment '~ Q I' documontary, educational, industrial, ielevislon" \I is not a critical item, jeopardizi~_ the large ex­ commeroial, and law enforcement movies. for \ penditure in labor and' time by tf~!;) use of the \ , Ii many years. Eight millimeter, once the $tandard \ \ I! '\ lower quality SUger-a would not seem justifiable. I size for amateur use, is ob$olete, replaced by For recording large number of PWUTIA tests, the with 31 percent greater ',' a Super-8~ a pict~re the lower operating cost plus the conditions area on the same filrn Width (4.1 x 5.8 mm, under which the movies are made would make' frame size compared to! 3.7 x 4.9 mm). The Super-8 the logical. choice. I choice for lawenforcerrr~nt purposes will be I I either the 16 mm or the Sjuper-8 size. " Ii All 16 mm equipment win be relatively high in /f initial cost, although in geneval the quality will be The big .advantage of 1~i mm motion pictures if3 ,high. There is a good supply of used 1'6 mm '. ! : in the quality of the picture. The variety of equirJ-· eqUipment, and high quality rental ,equipment is ment available for taking and projecting 16 mm ,:' available for the infrequent user. The, relative pictures, while not large c;ompared with the r operating cost wil/bS' about 6 times as high for variety available in tt)e Super-8 mm srnateuf .J 16 mm as fof Super-8. based., upon film price market, is ad~quate; They can be classified as I ) of high and very nigh quality. Sixteen millimeter and processing cost for a single original in ,/1 movie projection equipment is to be found all color, using,: the same type of· emulsion,and for ;;;,":1-;;" 'j over the country I,f'schools, institutions, clubs the same running time.lQlmthrSlzes~ Lo-cal,condi­ "~~:'~~"j:;;~~".' , tions with resp"'..,ci t()~-processing fac:ilitles and .~ .. " ~nd government, ~g~ncies, and is also used ~Y • film discounts will cause this flaure to vary from At the present time; the Polaroid Corporation " private concerns fo'r-E~ucational, training and In­ Ilzoom" lens and automatic exposure control, !:y::';;'~'::;'­ formation purposes, ' rather. than interchangeable lenses. Sixteen milli­ .department to department. mEtnufactures a full line of cameras, and· 000/" j "Sixty-Second" camera is available fro.ms"~n 1 meter cameras are invariably built around inter,;, , ,I As far as picture quality is concerned, the situa­ chang~able lenses, requiring a minimum (If independent manufacturer, The COIT.1P~xity of tion. is sir'i'lple~ Both 16 mm and Super-a use the three or four separate lenses. VMlable focal Instant Pr,ocess Cameras these cameras varies from a ,.$iihple scale same film width. The lenses of both sizes of length lenses are available as accEissories for . II focusing unit to a complet~!~",am6matici motor ! I cameras, if of standard quality, can image ri,uch all 16 mm cameras. They are very high q!Jal!!¥; ~ There are several instant proces({ systems of drive,. folding, singie len~lfefle)(' (the only folding photogrraphy. Prior to 1976, there was only one, SLR available). AIIJ."bffhese cameras, including o' I more information than the film is capable of lenses with a normal, focal length range of 10: 1 ~" r I manufadtured by the Polaroid" Corporation. the simplest~.Fc{tfii~e·· electronically controlled 'I recording. The 16 mm camera J~an provide pic­ and are correspondingly expensive. ' !i tures that cover almost thr~" times 9.S much Eastman Kodak introduced an" instant process shutte~~SfJffeds 1.0' automatically control the expo..: area with the same detail as the Super-8 or a fp most cases; good; motion pictures will require film ana camera system in the spring of 1976. In syre::Wlthin the range of c~nditions·that a particu- picture of the same area as the ~uper-8,~ut ~/a high~r:ordet of, skill on t~e part of the oper,ator one proce~s.a papernegativ~ is exposed in a,;I/far camera has been desigl9d to. cover. The special ~mE)ra or adapter. It is then automatigf;.!;i'· Po!aroi.d COrporation ha~ also introduced cam- " with almost twice as much detall~ '!anabhng~/ than will good stili pictures of the same subject. objects to be detected' in the 16 mm pic!~fe In ":laking m~tion ;,pictures, it is ~ommon Iy ooated With a viscous developing ag~!)t';ind eras with automatic focusing. Th~$e cameras .- that are half as large as the smallest dete~b~ pract~ce to' assign all of the processing to a rolled into contact with the paper po~itive as the are simple to operate, requiring minimal "sandwich" is removed from,ihe camera, oper~tor skill. Th~ picture sizes (!if the Polaroid l object in the Super-8. A single frame mm lab the fl' ~rf6 moti~n I>pictur~ pro~essing havin~ } film can be enlarged to make a !~~nt up to reqUired sp.eelal e9ulp~ent a~d ~xp~~lse to Printing proceeds to compl~tign by a chemical cameras~_.are limited to 6.5 x 8 cm '. diffu&ion process (ratherilan exposure to light)' (2'112 x 3"'1/4 in). 8 x 11 cm 0' 7.5 x 10 cm (3 x 4 in), asp~mpared to assure ~. high quahty ,JOb. ThiS ,slmphf.les the' 3.8 x 5 cm (,1 1/2 x 2 !n) for!::'lthe Super-a, operator s taSk., MOVies are dynamiC and between the sandwiched emUlsions until they (3 114 )( 4 1/4 in) ':and 8 x 8 cm before the detail begins to f~lIoff so rapidly that constantly changing. The operator- must b.e, able are separated in norm~J light This requires ap- (3'1/8 :.\ 3 1/8 in) in the case of the SLR. proximately 10 ser.:erid~ for film 1/ further enlargement is usel~s. t91 keep abreast ~f s~ch chang~s a~d aptlclpate . them, or the quality of the movies will be greatly (hence the instant process deSignation). It is a Eastman Kodak introduced two models Of its Sixteen millimeter equipment lacks some of the degraded. The operator must be alert and per- litht longer for color film. After separation, the camera during 1976, and plans to expand' ,jhe conveniEince feature$" that are' taken for granted ceptive over much longer time periods and to black and white positive requires a surface line to include more sophistioated cameras. The in Super-8. Almost all Super-8' cameras are many more things than is normally required in cleansing and coating with a preservative, Kodak cameras also incorporate autom~tic ex­ designed around a variable focal length or taking still pictures."" applied with a swab. In the color Polar6id posure control. Their picture size is 6~5 x 9 em process, this step has been eliminated. Both (2 1/2 x 3 1/2 in). 18 19

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o . _,'",,', " . "" ~"'~>'i:< .. '.1 ' "\.~4-~ ,:,.,. \"'!\ -"'I , ~ ". (f-~~::~." .' '\ .' .. ' ", • 8P 1e Canie~in, one 'positlon,. tnEr'nQ~}""gQ~o!.~~. c~r-" '~sefulhe$~ will. bl;~etern'in~(tby the operator's \\ " ...... 1··.! ',. A.d. t.ers ... 8. r:.e .'.. Er.V.B.iI .. ab. . w."h.J.Ch. 1I0.W i..n.· SJS.. n.•·.t '.'. t.he .... Origi.nal .•. . . process film to be used with view~. cameras,.", des.it~d.'lbn.·.~ratter.m~~e. . ' .... PiC~Y:~ "'~~.,. be.~n,_~ , . IS notched·.... . " the car'rleri!l7ir?petli"f~~~ment In s(;)lectmg. '. he 'photographs,as '. ." ,J . prftss' Camerll$iatrtf:t&~.",Sh.R cameras. ~ ", "'," .,.' . , " the. . of the' . the cartrldge~rather" :.. '. mufh',"~$ll.ythe camera'.s .t,e !ChI1ict,;llfl=l::Ittllrp.~ than to film, . >:.:~:,: " , ·Q~·Il§:."10.. ~ .. ,;.... ;~"~~... ".,.~,.n.... q' ..W\.O.'.i.d x 12,,5 ".t.iI.in cm,(4... ':.i.'.S... x \QYW5 In),...• ,ab. size,Ie .. for.'~.'l..and ab~~~¢'". the flash lamp automatically programs the cam- often. greater than the , "'~,:;;<"; .1' . '~\"'~T~~i~:g;(ldY@l'1tage ofthe instant process cam- pack of film, Wfllch costs mt\nY times the cost of era to properly 'expose for th~ .flashlamp andautom~ticcamera.il1 .. , ';;~S,: ' .. '(3r~'is~theabm!y~t(r$e~theptqture immediat~ly. equivalent materi~ls for the 'Same ,:J1berand ';" subject, either 'from the distancEf'for Which the and, higher q!Jalitylenses, higher . '. . '. ~.·,.Tbis"'isimpo~nt to ,the beginner or infrequent size of conventional photog~aphs,"'jc-Qsts the :(,) ""'-'·,l.c'P~mtE:!ra is focu°Sad in the Simpler automatics, or; . shutter speeds'and. in some cases; intercbarige- ,,,~~r.;-~fbr it alloWs, En'~ors infram!ng; focus. or ex- user the same"whether or not it producsspic- by . when, th~ proper amount . able lenses or" front lens elements, gTVingsome .P8~ to p~corrected4~t. the time the pictures tures, However"the cosis. are relatively fixed "" ' of,ljght has. the subject in choice offoc:~1 length. they find considerable , are'belhil taken .. Wifh· the . conventional photo- and predetermined. "- the more so'phisticated ones. . . use cin covert 'surveillance where a smaR incon- ,,0 ,. ":'lJraphic~~,su~l:t erro!s arerareiydetect~.d facfurer h~sannouncea 'the availability . " damera is required but something In time' ,toalt6w' corrective'sction.Jnstant Triere are a variety of specitJ purpose,cameras . aut()..f~cusing 35 ror;n camera. negativeisneces.~' . process cameras a~t . erefore excE!lIent for use and . accessories available, and" ·'the instant ',I !:'" .' inpffotogra~hic trarri' .~,In.a II;tW enforce~ prQcess camera can be an. outstanding tool for' These cameras (thE! ch:glily popular Kodak me.nt standpOint, how,ever, t' iliW tOU$~ tl'le the laW enforcement official. Like other tools,,,it Instamatic is a typical eX8'Q,lgle) have met a picture.as soon as it.i~.taken . " ,~-.more im-· ~hO~ld be used where .it~ characteristics fit th.~ definite ,need in tht'3 law enior£e~hbtield. !t portaoUb~n;tl,,\S-J\~!lltY !Q cOI!~~t ~iflU\k~s,;,. ;'"""cJC?~::. l'ltormal documentation, sup~lementaryalti< ShoUlg ~ot be forgotten, however.:1~at an auto- . ,. " '. ";\"~~,,,o,-,c-·v'f"r,::;~-.'o:~~-',·,,, ~ on smalier-casesthatdcH,!c;>~~,gMI!!lflJ!'mal pho- matic camer~ cannot select-for an""tl'!yestigatQr

. 'J'"l1ere 'are two .methods~! obtaln'lng" multmte',,,,,,~,,,~pgraphic .evi~entisl . coversQ.e, !l'~~'~~shots, :t" th~se. el~lTlent~ wh!ph are importafit()o. be II " prints frdm the .instantJcamera process (unless 'I~~?rnalsecunty badges '~ndslmllar use,s. recorded In ~ picture. Directi~ns for camQraop­ .\ the pictureo.is taken with a .positive-negative Instant prOfess photography, IS a .supplem~nt to, 'eratj01i![a,(~)in the instr.uction manual that Comes film): taking. as many pictures asrequir~d at the, and .not a substltutafQr. co~ventlonal photogra- ~ith eVe~(1artlt1~a;,~Qir~QtiOO~jQr~.!!'.~~!!,gc;~9.,9,~~_ timepf J:ihQ!ography, or copyi~g the original phy loJhe law enfc;>rce,ment field. pictures.. are mCl6h~Jnorec difficult tCf"-',';,';',S" oo.print. using" <'conventionalphotographic c: cbmmunicate.Photogral:)herS~da.vote a gOqtJ processes to make a negative~ Taking d~plicate part of their profe~~ional careers to perfecting~~' this technique. The automatic camera's <" pictures is impraCtical ... for any. subject inVOlvingA"J~rr.tatlc Cameras • ,'. .,:. 1/ mbtlon, living supjects,; facial .expressions, p,r position\JQf moving vehicles. In outdoor scer'les, ," Anautomjiti6 cfime~~ i$ one' in which ther Normal even the lighting change$ ... :l Multiple .' picture picture-taking actiori'sof "threading the camera taJiderrtification pictures from"~

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~~ , ", J/ il \. .' , . ,\'\., ...... ) 16 mm\'lJ1otidf' ··.piptore r~cords will ap~~ciate against the.. on WhiCh the print was so':".e .01 .' ~~e, di~lc;~'ties .' to.~be .expected·· irl:;~~he located,the' ligfitswere 'turn,ed,'~n,. t~e s~utter , Ir 'USf:) of the st.!/g-mlmaturecarnera. """, was released,anda same~slze negative Qfthe' Finger.prints woutdseem to be' an . .. .. '.. '.,. . Ii, ' ," \r '\\ \"" '~:._, ",' " _ lIlIC!c'in ... ,..... ""'''. ' matlc operation built into the camera rather thal1~ . " l '. ,I \" .' print resulted. In,;'spite ot all the progress .that . . ,', ma~e t9Q~#efffor th~' single lens.. the d. egree .of. rel.iability; ad. aptab •.ility,· resis ...... ·· n'c" e' &CI Ifa9Eit11erav h~Sl\~ '?"S .of good qUality, the fil~ '\ has b~en made, in other ar~as o.f-phot6graphy, reflex camera With macro lens and 'one of the t I Is always thefomltlngfacto~ .in ,the ~amera s \the ~~me '~qj;Jerprin~ camera is being ilss~ '.. automa1ic:el,ectro~i?flash .... Units, Either's.JripOd .~ norm~., fi,eld abuse, and a long 9ctmal; life' performance.: Thetheo~etlcal. maximum loday:,.," .. '~. '.' . "or 0.. ne o,f. m... e, . man. y macro orc:losGeup" lIlI,.,tt, "s"'h-., Wlthout",ma'!!tenan~e. The I~we'nforc:ement . , I., re~oh",.i~i)Jhatcan .'be~;ob41if'l,e~,fromaf1Y f/2 '. '\ ' ,ments SlIplls( to that prOVided on the j~st;n-t", ,official C:hoOSi~~,.." photographic E:lqul~ment . ,c<-::~">,_ Jeans ISI\approximately 10crUnepairsper?1i11ime- A .1iQ,gerprint camera Js a simple . earners, pro.ce.ss kit w. ou.ld,. en. able most fing' erprin.·. t assign- . s~ould keep thiS 'fiQ,~1 the fo"o~ing points in t t b mlQd. ~~\, (c; men ~ 0 e'ha~~led With comparativeeflSEI. . ".' " '. .' "..... I:'. r;:.m.I,an.. y-a... v... al.l.a ..b.I ...... a. r.e.. ' alm.ostth. a.'.t g.... OO....d..... d. t.o.. do ?ne. jO.b.. :..• ... B..k .8.' fUI.,-.size. .. s. :~~'. "'~:",,~~",~~,c"'" 1 ·//t~. 'Ther~ are. very fe~e.J.~n films ~.~s that apprqcachthat ofeS.!Qn~~ f,"gerp'rtn~, slr:1gle or whole~ hand (orre?O~d slmlhjlr at first glance the A. When' ooe .particolar only : ' .. ", "figure, however.. MQ,~!I~ these are extremely .marks, . slll;hast . e~r-prints). It i~ a. specisll- ~~,Altho~gh fing~rprint' probl~m tyP~,(~4bject f WOI,J.!Z,. seem to be one that CQuld .well be must be reeorde~,andltcan ."~ closely :-~'{f . '. ~Iow, very high c'Ootr~st films ~hat are purpose catVl,era whichre.q(lir'esbasic~IJY. (10 . ,_.~\completeIY .Ilnsl..'ite~ to \~epurp?~e$.for"~t:l.ich operating adju$~ments by the,'operator, ,and h~s ' han~led by an automatic typeof.camera " controlled, ,automaticeqyipment cando~,mUch" ." "v~~would IIl

t teiistics. SlncEJpackaglng . of' fjlm for sub-minis". ~utomatic .in .the sense, t~at they warn when exp~rieliced photographer with his more,., operators under a of lJ~famil!ar condi- .~turf!p is not standardized;. it is common practice things are going wrong. A we,ak set of batteries vers~tile equipment will probably still be tions, ' to obtain a. sto~e of cartridge~ to fit"thecat:nera . w.:: . cameras, made b~ .all of·th~'major.manufabtur- . It'l; . . ets, f9}~wthe general aytbmatic operation of ._~e~_~IJ.=..~!3~ignedC to appeal to the inherent '". '!ih~ size' of the "subject of photographers to equate graphed is· one of the first corlcen1S ~ '\~~e .I~s~~aticsy.~~,!,__ e~ept,~!or cam~r~ size "-\tmdeney~ excellence of equipment with excf3l1ence of. pic- ting a camera. for it is a ',..,,'" ...... 11 I.'" '. !a~d~'~.!Mf,_Jormat~ The PO,eRet InstamatujJS~Q,~! ) ro...... t~r~s. ,Excellence of equipmenti" this conteXt size of the image 'th'at will be r ";rn~ c",,~.,,~~,=.=· .'~Jrf.<. 0t'" •. ",~ ~.:-"iu~a~r,n!3ra bllt" a coordinated system of car-'" ""tridge .C?l9r, .. film, camera and projector, nor:{I1ally is taken to mean the degre~ of auto- presents a general classification deSigned for:·,PloducinQ transparencies of color negatives ancfprints:ltmay be of particular use '''insomecovert surveillance,sinc;::e it is an amatE!ur' type ·of camera, rather than a profes­ sionaltype.· and may 'attract less 'afta'ltion for thi$ reason." . Instant fingerprint recor~s can now be obtained . ,. F.lngerprlntCameras by an instant process 6amera kit which utiliiesa •..... ' .... l-' '\ ,guide fastened to 'the,front of ·the cam­ Ih@. need to conveniently r~cord fingerprints, at era. When thi~ is placed against~l'fla!. surface, it .~ perfod Y!t"!en.cameras specifically desigoedfor steadies the' .9amera, ·.keeps . it tfie ····.proper .~JQie~up;:'sm~!i"",,q,bj~J . phot~grap~y'~~r!_ not distance from the '. st.lrface to' aS8.f:JJe a sharply .,? .'availableJ~'le(t .to thedevelopmem of the "'5. 5 inf~)~)carnera specifically for taking, " 22

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.. _ di~cussed'" in more detail ·In the sectjon of this manis, or the ability to handle"1~lt action. A , ~, ' " '~"bUi~~ttfat1(jn6Ws;'" ~ .. ..,.. ,..... Cllfi!:l~lisl·QLp@roe,r~Ulbaracteristics t'fta~hould , .t\0 be,conEljge[(:td· .,when selecting, a ,camera'::is»~t LENSES

i •• ••,,_ .. The (selaction :of a camera wi!" also be thEr'Eincfof this section. One special characteri$'> I { R influeri~ed by th!3 manner in which the su~ject ~ Jp4iic is .. conspicuous by its absence:' personal pref- j 1 ,1I,umine\ed ~~ther ~Y exi~ting lig~t or s~pple- erence or k~own skills of your photogrsphars "'~ '''' J ~e~ta~ 1~~h1In!J)! onf the s~~ject IS moving or with specific types of equipment. In using the ,. ",~1,~~;7~'" Statlona~. - '" ~. 0' ~':~cbecklist, YQU, can set your oWn requirement for o "'N ..:; . "''' . each char~cteristi(fDaSeduponwharyou wouj'd " :" While thls\gulde places emphaSIS on.-:.~he selee- consider to be ideal for your application and Ii" ' ~,'. L'" '" tion, of 'eqOipment to obtain the highest quality"'rate the various carrieras that you are consider- . photograpH possible, not all choices can or ing accordingly.', " I; .:',,'. f~~= ,__shouldbe based SOI~IYUpon.nega~~ve quality.

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Lenses extend the police photo­ grapher's ability to gather eViden6e .. by it possible' to obtain photographs wide range of conditions.

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'.i acc,:essory lens is want~d. In the,'professional (combinations of a number ofsimpfe If;lnsas), I fieRi, particularly With press and view cameras,it hoy.tever,' and methods of measuring the lens to

"\ is common practice for the photographer' to filrh distance are complicate'(J. There' is no '. I \~ // make his own selection of lenses and have readily identifia,ble point, in a I~hs. which may' be '>.) ..... , T 'W . "aM 11 WU' .)i3 t,,, t 'S,...b. them fitted to the camera of his choice. Some two or more inches thick, from., Which" to lenses that eminently fill special n~eds are avail" measure; so We speak of the "equivale"t focal . '. \ . able from one or two manufacturers only, and length" of a photographic lens, referring to the .Depending upon the assignment, the photogra­ assures 'tha~thea~tomati~~r preset diaphragm such manufacturers are normally lens f~~al length of the simple' lens that would give' '"," pher will nee~ a wide-angle, normal, or long­ u~ed on so many .slngle lens reflex cameras will specialists and not cameramanufacturers~ the same image. size~ All photographic lenses focus lens to record' the. subject of interest. 'be properly mated mec~anically to the are marked with a focal lehgth. This is a· Aside from the obvious requirement that the mechanism that is a part ,0fJJ\~ lens. The manu­ The great variety of 35 mm single lens reflex nominal valuE3 .and is normally within 5 percent .. , lens must flt'the camera that'it will beused'with, facturers of most cameras with interchangeable cameras has brought into th~ market a Jarg'e seN' of the actual focal length. lectionof "universal" Brand-X/enses, designed the selection ~iII boil down to foc~' length lenses provide some selecti6n of lenses of J (which determines the size of tha image) and varying charscte'ristics for use d~ their ~ameras. to fit many makes and models of single lens . For the rapid calculation of image size, it is con- reflex, rangefinder and other $5 mm cameras. venient for the photographer working in the field f·number (Which. determines how bright the Some 35 m. m . single lens .s.e;flex cameras image Is), NaturaJlY, one is also interested in the provide a choice of 20 or '!lore lenses of All of these lenses ,are made by independent to know the "coverage" ratio of each lens-cam­ lens manufacturers and they supply 'adapters Iim't~ of use of a specific lens" suches general various' focal lengths, speeds, ~mgles of view to era com~ination which he uses. This figure will purpose, macro, or process; , and special use characteristics. \. fit the lenses to most popular cameras. Why quickly give him, with' only a{ rough merital . ,'" > .' _.--'--.... -. use Brand-X lenses for professional work? In calculation, tlie'total field of the came fa. The o In most . cases, . one will select a lens that is Why look elsewhere than to the original manu­ general, they are of high quality, as good as maximum dimension (height or width) of the neg­ prQvi~~; 'by the camera manufacturer and facturer of t~'le damera for an additional lens? those furnished by the camera manufacturer. ative divided by the focal length of the lens is designEld for 'use on that partipular· camera. The Two·reasons. Not all camera manufacturers are Many times, they provide an in~between selec­ the coverage ratio. For any object at any lens mounts,:will fit properly and assure that the lens mant,dacturers, although a great' many are. tion of focal length, speed or some other charac­ distance, the distance times "the coverage ratio .- 'If' lens Is In the proper positloft for focusing. It also You may be forced to buy a Brand-X lens if an teristic desired by the professional, that is not . for that lens·'camera' combinhtion will give the avail~ble 'in the camera manufacturer's line of maximum field of the camera. lenses. Because of larger production in some Popular models, prices' may be lower than for For example, a35 mm camera (36 mm maxi­ the equivalent lenses as available from the cam­ mum negative dimension) and a 50 mm lens 1 era manufacturer. The user of good quality have a coverage ratio of 36/50, which equals I, "universa'" accessory lenses will normally be 0'.72 oJ' approximately 7/10. If the subject of I satisfied with them, but he must assure himSelf interest is 100 feet from the camera, the total that the desired lens is properly adapted to the field of view is 7/10 of 100, or 70 feet. A 6-foot particular CSmen! on which it is to be used. man is a very small portion (somewhat less than 10%) of the field of view, so his image is gOing Image Size to be an equally small percent of the total length olthe picture (less than 35 mm). Notice t The size of the image that a lens forms is that it does n'ot matter in~ what units the lens I determined by three things: the size of the sub­ focal length is marked, as long as you figure the ject, the distance from the camera to the sub­ coverage ratio using the same. units for the ject, and the focal length of the camera lens. length of the negative. Similarly, the calculated The ratio between the size of the image and the figure for the camera field of ",iew will be in the focal length of the lens, for subjects which are same units you use to measure the distance: at least focal lengths from the camera, meters, feet, yards; etc: 1\ i 10 will ),' . 'II . t,r I',{ , , be the same as the ratio between the size of Q ~ •• , , the subject and its distance from the lens. c' As another example, consider two cameras, a 16 mm movie camera and a 35 mm Single lens Focal length is an inherent "designed-in'! reflex, both with 50 mm lenses .. For the 16 mm ( .. . ,~ . property of every lens. For a simple thin lens camera, the coverage ratio is 10.3/50 or approx­ IT!~de of a .single piece of glass, it is the imately 2/10. For the 35 mm camera, the distance from·the center of the lens to the film coverage ratio i$ 36/50 or approximately 7/10. ~- ,l wh~n a very distant object is sharply focused on At 20 feet, the field of view of the 16 mm cam­ the \fllm. Photographic lenses are thick lenses era is 2/10 times 20 or 4 feet. The picture will , . 26 27

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h,cfL@eonly ,,2/3 of a', ~~fo~t 9ubject.For lhe This ratio is called .the relative aperture of the ~5nim camera at 20'feet;ttee field Of view ,is lens. The amoun~ of light reachingcthe film Will multiply the f~number'by two, 'the diaphragm represent a change of a full stop but only " .,/1 o'tUnes 20 or ·14 feet. The 6-footsubjec~ will be the same for any' specific relative aperture, area will be decreased by, two squared or. four ~tenths of estop from maximUITiJi)perture. coverabouf.h$lfthe. negative. Table2,givesthe regardless of the focal length of the lens. The (requiring an exp'bsure duration fOlAr times as This must ,not be forgotten sine,e the change for QOY(;lrllge r~tiosfQr some cOi'ntnolJly used image •relative aperture is the f-numbfi)r or stop of the long as' the6riginal to produce the same effect the first aperture stop is not 'always a fun stop ,$i;08: an,d lensf3s~ , lens; if the focal length is twice the diameter of on'the film). Since it takes two multipleso~ two on a great many lenses. J !' oJ~ ..q·""o;;the aperture, t~~ ratio is 2/1, or, 2 and it is for the new exposure, it is spoken of as an expo­ Lens Speed. . Written as 112. "Similarly, if the fdbal lengt;, is sure increase of two stops. Speed, .in a lens.~as,determined by the relative four times the dia'!leter of the aperture, the ratio apertu~e, lets, us know how long we 'have to ,.Table 3 will make this a little clearer. It speed is subject of ,interest and is4 and"the f"number is f/4. Note that the size; expose the film. USing table 2. we find that. With Lens 8' compares, starting With a relative aperture of confusion to beginning') Photographers and. to of the 0 aperture for a given focal. length an 1/1.4 lensi the light can be one-eighth as , f/1.4, the standard f·numbers which are o those not well versed in . A is like decreases as the f-number increases. Thus, the bright as'Viith an f/4 and still allow the same q~mera normally used "for marking relative apertures, ,a, closed'rooni With a window in the center of brightness of the image"on the film decreases length .,e~rPoSiJre. For the sal1)e brightness of the iotai number of stops of exposure c;hange ons end.wa") and the film on the center of the withincreasing,f-number. light on the, subject, the shutter speed can be" which they represent, and the relative shorteneCi by a factor, of eight. For the lawen- oPPPsite wall. The ligllt reac~ing' the iilm brightness of the image on the film with respect through a large window(:' will be quite bright, It is convenient in photography to vary the , forcement photographer, lens speed is of the 'to the image at f/1.4. In gOingoirom f/1.4 to fl22 while much .Iess light will reach the. film thvough ", length of time that light is allowed to act on film greatest ,value in a covert surveillance situation (a normal range.for a lens of this speed) the ex­ where supplementary illumination cannot be a small window. Similarly, for a given\~lndow by factors of· two to one. So lens diaphragms posure is increased by eight stops and the used and the difference between an fl1.2 and size, the amount" of light Oil the film will are marked with a series of relative aperture image on the film is 1/256 or 0.0039 times as decrease if the room beco~tes, longer. The numbers that!. have a tWo to one exposure factor an fl1.4.lens may mean not getting a picture bright as the original image. with the fl1.4. amount, of light, reaching the I film, then~ is' a between adjacent stop numbers. ,The opening in function oftha length 'of tl1e "room (th~y focal the lens diaphragm is circular, and it is the area MOGt lenses have tM maximum relative apera , Depth of field is another import~,nt factor. The length of the lens) a.nd the size 01 the window of the aperture that determines how bright .the ture (smallest f-number) marked on the lens and nearest. object of interest and ~he, most distant (the diameter of the aperture or diaphragm of film image is. Doubling the diameter of a circle as the first stop on the aperture control. The one must both b~i sharply focused at the same the lens)~ SpecificallY. the amo'unt of light makes its area four times as great; thus, our next stop marked on the aperture control will be 'time; 'ther or not they will be is dependent reaching' the, film is determined by t~e ratio of f-numbers will have an inverse-square rela­ the next larger one of the above series of stand;. em seve . factors, all of which must be " the focal length to the diameter of the aperture. tionship with the r~uired exposure. If we ard stops. For instance, on an f 11.7 lens, the balanced against e~h other. A large depth of ,i, next marked stop ,~ould be f/2. This does' n8t field is particularly important when the' amount :J .. Table2. FIELD COVERAGE RATIOS , .... Table 3. LIST OF STANDARD f-NUMBERS

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" ~ I ' Still, other' factors are pertinent to the subject of si4lst/ons where the mmdmum obtainable lens visualized as a cOne which ~ld'::ll1ds forward: lenS: apeed;speed is qbtainable only by, the speed: is the only way to'g9t a pich,ire. "from the .center. 01 the' lens, spre~ding; out sacrifice of' oUler qu~lities. The ~acrifices around· its. 'optical' axis to infinity. The' angle reqoiredfor extreme speed 'iQ lens~~s used i' ~~, "', ~!n~:2~~!i~[S,_ t~~ !t{ considered. between. the ~ides: of ~f'liscone is the angular J I primarily for general ~aW' enforcement photogra­ , Whenever IIgllt. stnRes the surface ofa glass coverage of the lens.. Simijarly, S' $Scond cqne I phy do not' produce corresponding benefits. leriS~ about 4 to 5 percent ·of· it is reflected'back extends from the lens on the.' image si~e of the Covering power must be sacrificed for speed; in from the surface, a much smaller amount is. I~ns to. the film; the' angle afthis tiOne is the D gene1:~"even rnoderatery wide angle lens.es will absorbed In passing through the glass and the frme .~s the viewlng'.ang,fe~ .Whether: the; ,im~ge 1 be one or two stops. slower thane lenses with balance is transmitted througJl the glsfls to the completely" covers the negative d~pends, upon 1. opposite surface, where again about 4 percent smaller angurar coverages. As speed is the focallengthr the angular cover~ge, ,and the 'I increased, size and weight go UP' rapidly. A two­ is reflected back to the first surface. Thus, siz;eof the negative. The image that\\is, formed is I stop increase in speed automatically dou,~les about 8 percent of the light is loist for' every circular, ,while the', negatiw~ is' ':square' or the diameter of the lens. In addition, the internal . element in the lens which is' boundiad by 'air on rectangular. The dim,ension of concern, then, is construction must be made more complex, both sides. For a 6-alement uncoated lens, the the diagonal measu~ement of th.e negative~ I.] requiring 8, 10 or even "'mor~ optical elements total light leaving the .Iens is about. half of that wh~e 4, 5, or 6 were SUfficient on the slower entering it With a complex with 15 to It is readily ·apparent that" if the area of the lenS. The more complex lens Will be physically 20 elements, the .light IElavil'lg,the lens would be' just covers a 35 'mm negative, it longer than the simpler Ohe, and this in turn only a small part of that entering~ . will only partially cover the ~\rea, of a 6 x'6 cm requires still larger diameter front and rear negative. Thus, if the same focal length lens is elements to prevent light cuf.:off or' . By coating each lens surface with a layer of to be used on a larger film size camera, the magnesium fluoride or similar matenal, the o The· weight and size are thus increased still angular coverage of the lens must be increased of enlargement to be given the negative is;-~.' more. reflection losses can be reduced. The layer to provide an image at least as l~rge as the film. must have a uniform thickr)ess of exactly 1/4 of In the case.of a.view camera, Which haS distor­ ~~:a~_I'1~~~~~:fe~~~ ~~~:I~si~a~::'i~~:,,~::~ Focusing range, in gener~I, is also sacrificed for a wavelength of light With this technique, the tion control adjustments, the ,~\ngolar cov~~age ,length is short, and the nearest object distance speed. The more complex lens designs are light reflected at each surface for one particular must result in an image' area' twen larger than o is large: Conversely, a very shallow usable much more sensitive to changes in' object wavelength 'can be reduced to ADout 112 the film· size. The lens manufelcturer will state depth ;,of field is obtained when the, lens disfance than the simpler designs. An f/1.2 lens . percent, with an" overall reflection for all angular coverage eitlierin degrees or in terms f-namber Is small, the lens focal length is I,vge, may' show a definite fall-off in sharpness when wavelengths of 1 to 2 percent per surface of the maximum film size that will be covered by and the near object is very close to the cam~ra. used at 3 feet while a corresponding fl2,8 lens instead of the normal 4 percelnt. or more. 'By the lens when it is focused at infinity~ Thest:l requirements are obviously conflicting, may give sharp pictures down to' 12 inches. using more complex coatings with 7 or 8 layers' and different materials, the reflectance per and' ttfe lens aperture or f-number is normally Such problems are generally only discovered by . The normal lenses for any cameral will have an surface can be brought· down an overall the one which can be most easily adjusted to actual experience with the lens, at which point it to angular coverage of 45 to 50 degrees when figure of 1/2 percent. These multi-layer high­ get the desire~ depth of field. Focal length mLlst is too' late., to cOrrect the problem,1 Many ultra- used on the film size for which 1hey were efficiency coatings are being increasingly be chosen based on required image size; the fast lenses cannot be stopped down beyond designed; Their coverage ratio Will be approxi­ applied to newly designed lenses. The resulting near and far objects are where we find them; about f/11 or fl16, and, neutral density filters mately 0:7 ,to 1.0. They produce.8 pleasing per­ and the. negatiye size determines the ,amount of mu~f be added for bright light conditions. For increased light transmission is of great value in spective in the negative and will lead to natural . enlargement The working photographer quickly general purpose work, lenses with 'apertures in complex zoom and extreme wide angle lenses appearances and convenient 'f'iewingdistances. of many elements. What is of equal importance finds that his, sharpest pictures tend to be shot the range of fl2 to f/4 will be found adequate, In moyie cameras, the tendency is to use; a is that the light from internal reflections in an :1 atlarge f.n~mbers. with those. faster than f/2 reserved for special normal lens with a considerably 6maller angular 'uncoated lens may be reflected back to the film , coverage, generally about 30 to' 35 degrees. l In the form of stray light that fogs the film and This Is partly, for convenience in filming; the sub­ decreases the image contrast, degrading image· ject is. further from the cam~lra and· so does not resolution •. The Rlulti.laYer coating prevents this go ou~ of focus so easily, tiS it moves around. degradation, which is particularly noticeable in a Table"4 lists the length of the film diagonal, the back-lighted subject. normal lens focal length (which is approximately equal to the diagonal) and the minimum angular Angular Coverage coverage for soversl picturEt siles.

~-::; As previously discussed, the size of the· image The law enforcement phc)tographer will have formed by a lens depends solely c:pon' the frequent need for other than normal. focal length ~ Dept!jJof Fleld~. distance to the subject and the focal length of lenses. These too are tabulated in table 4. Wide the lens. The field of" view of the lens can be angle lenses are defined as lenses thin are \) ----~--~~~------30 - acteristic is that the distance from the '. front of " deslgn,ed toprovide~ mucb greQter than nornial lenses covering 180 degrees to 220 degrees image size regardless of the camara with which angular coveragtf when used' with the picture are available for many picture sizes and camera the lens to the film is much less than the focal they are used. they may not be 'equally: SUitable srze' for which they were designed. They are models. These extreme coverages are obtained length of the lensj, that iS,it gives a long I~)cal be'1,a~se of the. large magnificati9" to which sur­ length in a short lens.' The term t~lephoto always of shorter focal length than the 'normal only, at t~e ,expense of great distortion .. Straight veillance negatives, ara .. rtp.!ma,I~k~ubj~cted~ A ,. !~n$es fbr a glveh picture size., rhis ~as lead to lines a short distance from the lens axis are , should' be restricted to lensas of this type, and 300mm lens for a 20 eX' 25 cm ($ xf(rin)' view' rile misconception that all short focal length greatly bowed and appearr in the picture as the, term "tele .. lens" or long~focus lens used as camera. is designtfd to have ~~ wide angular " lenses are wide angle, which is incorrect. Ail though .,curved. Such lenses have little applica­ the general term for lenses used to provide coverage, and this may involve a \~acrifice ()fpic~ lenses with angular coverag$s exce/ading 50 to tion to n:~w enforcement use. large images of distant subjects. Coverage ture sharpness near the center of the field. l 60 degrees, are wide angle lenses. Their" ratios for tele-Ienses will be small. from about Such a lens would produce results inferior to Ii coverage ratios will be' much greater than 1. The ,opposife'''of the wide angl~ lensislhe 0.5 to 0.05 or less. th6~e of a 30o:fiiiTflens designed for use on a f I:ven a wide angle lens' can become a normal narrow angle or long-focus lens, commonly mis­ single lens reflex with maximum center fens if ,it. is' used on a sufficiently smaller··film called the' IItelephoto" lens., The term telephoto, .resolution. The only simple (way to tell whether size' than' it was intended for, beoause of the' although commonly used, may:;')be incorrect; .' the is usable is to test the two lelnseson the a,ame subject. In general, the lens t{ reduced angular field of the image that is optically, a telephoto lens ~a's a special deSign. recorded~ Lenses with coverage angles. of 100 It is coroo9sedof .. ;:;two combinations of designed for the smallfi3r negative size will or more degrees are generally considered to be elements, a,·-negative or

I infra- iIIuminati0rJ. If it is not present, increase There is a very wide selection of long40cus the lens to film distance, after vh;;ual focusing, lenses. available today. These are very useful in by about 5 percent of the focal length of the surveillance photography, in which image size is lens and make tests about this paint to of crucial importance. Howev~r, while all determine the position giving the sharpest 300 mm lenses, for example, provide the same image. i-, l,~

33

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. ~, .~...... :-~~~,.;;:,-- ~7. i.l ;~ ,: " .' ... ';, " \,. ' .. ' .~ .::. '-. ·-"Co, -t~'''l'' . necessaryfQr any impossible. It was the 'zoom with rna,nUY'ir.1f , ", Withini,tslimits,ai~igh\qyality g~ri~ral purpose Wh'eh the image thatJsJormed becomes larger ;; ,;f)', -"~-~'Coth.~~~s otherphotogr:~Phic\:) )~~ot fUll?ose.~~WIt~e ,afix~d,popY\lcame.ra ,is setup. ' the a#ributes of the 'dolly 'shot 'a~d none the .- __ ,,'phot()graphicle~s ~ill~rovi.~!J'l'Ipre~e~i!, in it,s than the "subject, hO~$r, the, rules reverse. f, " , or diffic41tYJn performing"it, that' in.Sp!red l'1lsge .t~an the average,)!ll'llcan recor(j~'EQ-l.. For larger than actual size images, short-focus~ :'r :1 l" ',; ,',. ·d,9cu/ment.-l¥p:O~MQ,ti,,-~n,,?f all. type$,~he th.Q,devl3l~ proc~ss. ens IS ,,\hel:)est Cliol~.~Jor 'pr,oduclng opm.ent of the moder.nzocm '1~'J':I~i? ~"TV""~::~''''~' certain (:~pecial, "subieetsl"'>'nowever~~~ 7special:~'~i.~n~!~_ ~~oduC?e lar9~rimages for· a give!}! lef1s"=-·~t '"Co .' • t ,.. the highest qll!Bii1\Y wor/( . '~>"' ___ 7/ ':,. , . nS"i<: i I .t.,~,· "" .lenses:s~ould be used. Th~seare listed ~elow to-fitm-afslance=than,",-Jong-focus lensesjand l . ::,'''-" '. ' . iI I,' ii', -~t'0_'~~~_~,",<:'--··z~omlens. ~~solution i,s.notas:iI11Portant;asin ,. intheprd?r Of,t~r~r importancEl' ' 10ng-fQcus lensc;!s ~ave moreCJeplh'oHield tb~.n. 1 " . , .. . ..' ". Ii/ " . ...•• t -,=---.%~!I,o~n~n:o~,e lenses, since the TV system taas ,- 1/"', ' 0 short·focus lenses. There is no -sudden reversal - '-- '~OQm.fttVarl,~blefocuSlenses·" a very~I~~~solution ~omparedto film. Ught 'ifit the rules; rather, the trends t~at have iil.. .: ...... , .'.: . .=,., " .". ..tr~nsmis~lon~~nd--c-Q.Qt!~t ~re more impQrtant Tflls type of lens IS a re.latlve newcomer to the, for TV use.--=-'=.~-;:~_ " , . ,governed image behavior when the)mCJ,ge is 'I\, , smaller'··-than' the"'subject become less' well .photographicfield. The modemzoom\\ I$ns has .'. ."<. . '.' .' ". • <;"""

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,," '.' .rang~. Ooe af,twomanu!licturers sUPP,ly 'en~~s ~When it comes your Q,wn equipment ""on its own special merits. One gr~atly respected telescopes. \~" before buyi .... g one. . astronomical telescope (the Questar) "isavail- "';--­ ,~'" ' Reflectl,.n", II or C~,tadlo,ptrlc Lenses able in" a model' whiCh has been, modified for , U use with a Single lens reflex, 35 min camera. for There is a fairly good. selection, efspecial IQng: strictly photographic use. The telescope and focus lenses oftha catadioptric type. These are camf\l"a com~ined are lessthsn 16 inches long, " combinations of lenses and mirrors,' used to snd provide a focal length of 1400 mm or more, prd.~uce ~ffects thatcar.'lnot be obtained by' depending on the extension tubes used. The len~\s ,alone. ',Their focal lengths are normally total system is very cC)f)venieht to use. 500 inm' or mOre. These lenses are noted for I

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EXPOSURE METERS

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Use of exposure meters can insure the photographer of consistent proper exposure

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lens. Because of the way in which the cell measuring exposure for extreme long--focus resP9r.ds to light, this is difficult to. do lenses, since it sees only what the lens sees. regardless of whether the barrier layer or the CdS cell is used. The disadvantages of the spot meter 'are: it is -oil time,·nonsuming to use, since many pOints on , \i o The inCident- uses a different the subject must be read and the exposure is .,' \11 I, .~ . II approach. ft looks at the. light which i~ reaching /' computed from the brightest and darkest Ansxposure meter of some tYpe is anes$ential pro~,Ortional to the brightness of the light. This the·subj6ct from all directions. The meter ~ faces elements. of major importance; it is larger and part of the working kit of every law enforcement typel,1 of cell has the "advantage of not requiring toward the light source and infers the proper ex­ more expensive than either the incident or photographer. . With it, .. the photographer any battery, but its ability to measure weak or posure from this Iight"JU.oo, uses either type of 1 reflected-light meters; and it requires more 1 measures the illumination coming from the sub­ dim light is limited. The second type,the photo~ photocell. (' " judgment on the part oOhe user." ject and entering' the camera lens. For every conductive photocell, has a resistancsthat is lens aperture and ,' there is a unique inve'rsely proportional to the illumination falling The advantages of the incident-light meter are: There is a fourth type of exposure meteI', product of illumination and time in secor:lds that on it. A miniature battery is used to provide the it tends to record all parts of the subject at originally used in photomicrography but represents the total amountiof light req4ired to source of electric current. The photocell density levels which correspond. to their relative currenW found in a modified form in most single produce the optimum densitY in the developed controls the current, which is measured on a brightnesses; it is not ~ffected by the proportic;m lens Jeflex cameras with built-in exposure ,film. The' exposure meter measures the iIIumina­ "sensitive ammeter. This type of photocell has of light to dark areas in the subject, but only the " ,control. This meter has the high sensitivity to . tiqn, and the calculator ifltO, which tb~ ASA. film the advantage of being very much smaller than brightness of the light falling on the subject; it is dim ligHt provided by ~he photoconductor, the speed has been entered is used to compute the " the barrier layer cell and very much more more useful in very'! dim illumination, since it small area' reading capabilities of the spot ,length of time' the light {rom each lens aperture sensitive'tcfdim light. The most commonly used measures the total incidant illumination, which is meter, and much of the tolerance of the incident '\'tnustbe allowed to act. photocell Of this, ,wpe is the cadmium sulphide, . ~Iways more than the reflected illumination. type meter for' bright subject areas. In 1::1 •• or CdS~ 'cell. Silidon photodiodes, which provide photomicrography, a probe-type of exposure E~pOSUl'e meters 'as" separate units are not as a· greater sensitivity .to changing light levels, are The disadvantages of the incident-light meter meter witn a very small photocell is used to important as they once were because of the replacing the CdS cell, and more recently, some are: it should be used from· the subject position, measure th~iH;)rightness of the image directly. in widespread U~e of cameras with built-in meters manufacturers have started to use gallium with the mett3r faCing toward the camera; it is the film plane of .the camera. The same and automatic .'exposure controls; The essential ~arsenide-ph()sphide (GAsP) ceils, which are the not generally usable for s;Jbjects which are prinCiple is used in the single lens reflex camera principles of operation and use are, however, most sensitive of the photocells presently avail­ themselves luminous, but. only with those that having a through-tha-Iens metering system. This r the same for separate meters and built-in able. are luminous because they reflect light which is uses one or more photocells, placed in the falling on them from an external source. meters. ' optical system so that c' they measure the Th(;l ,refl~cted-light meter h~s the following ad­ brightness of the image on the viewing, screen. ,Separate exposure meters are of two general Many the available professional meters are vantages: it is small, rugged, relatively ine~pen­ of Two types of adjusting system are usect;Jn the deSigned for use with either ref'~cted light or type~: incident light and reflected light. Built-in sive, and requires no upkeep if of the barrier stop-down manual system, there 'is\, no' exposure meters of the types normally used in incident light. This is the ideal system, since it layer type; can be used from the camera connection between the lens diaphragm \~mcf provides maximum flexibility for use under single I~ns'reflex cameras are almosf-universal­ position; can be filtered to see i~1 .about the exposure meter. The lens is stopped down, \ unusual p,o'nditions: the consistency of the Iy of 'the reflected-light type. A third type of the same relations as the film sees them; and manually until the meter indicatur is centered. ' meter, which is found less frequently, is, the spot incident-light meter and the ability of the has a reasonably long life. The image is then the right brightness on:-th~ reflected-light meter to deal with selt-Iuminous meter. It too is found as both a separate and a viewing screen and the lens is at'the,proper ap- :., ".-, built-in meter. The i~tegrating or flash meter is . Its, disadvantages are: its field of view should subjects . "'.'~,j;: another type. match that of the camera lens but is generally larger; it ,is influenced too much by small areas A third type of exposure meter is the spot meter. It is ~asically a reflected-light meter The r~flected-lightmeter, which was th~~first of of bright' illumination in the subject, tending to "the electric exposure meters tf) be used and is expose for the brightest area and underexpose which has been placed behind a telescope so still' the most commonly encountered, is simple much darker ones; it is unduly influenced by the that the se~sing photocell sees only a very tiny In ptinciple. A 'photoelectric cell (photocell) is overall ligptness or. darknessqf the subject, area of the \~ubject. Each small element of the .. " placed in a position near the camera lens and tending to. ,expose so as to~ offset these subject can" have its brightness measured arranged to receive light from about the same differences; while it looks at a subject from ,the directly by the meter from the camera position. angle as an "average" camera lens. Two types same position as the camera lens, it does not The advantages of the spot meter are: it sees of photocells may be used with all types of expo­ respond to light in the same fashion as the lens­ and responds to each spot in the 'subject in the sure meters. One type, the photovoltaic, (barrier fifm' combination. Some type of shield or baffle ' same way that the corresponding area of the ' layer) directly converts the light into an electri­ is essential in order to limit the light reaching' film in the camera does; it can be used from the cal' current which is measured by a sem~jtive the cell to that coming from th~ same direction camera position' to measure exposure on as 'that reaching the '. film through' 1he camera ammeter. The amount of the curr~nt Is directly inaccessible subjects; and it is' ideal' for

40 41

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.1

i .', erturefor taking the picture. This; system can be Exposure meters using CdS d~tectors are used with any lena on the·. camerajsinee accurate over a . broad range Of~ illumination diaphragm coupling is unnece'ssary. However. "it levels; howeve~, they suffer a 10SSIlOf sensitivity forces. the photographer to' always work with a . at low Ught levels immediately following use stopped-down image on the viewing screen, under conditions of bright illumination. The CdS which" may give problems in poor light. detector will slowly recover full low light level sensitivity over a period of mahy minutes, but FILM' ':" The alternate system. which requires mechani­ may not provide correct exposures, if one takes calcqopling between the lens 'diaphragm pictures outdoors and immediately attempts to control and toe. is. the one more meter.~ use the detector in a dimly lighted interior. 1 commonly used. .As the diaphr~gm o,control on Several manufacturers have introduced cam­ the .. lens. is operated to adjust" the exposure eras that" replace thEl CdS deJtectors with~i1icon meter indicator, the I~ns is not a.ctually stopped photodiodes or, gallium arsenide-phosphide down. but the corresponding sto~' is preset into celis, b9,fn, of which are much more sensitive <) 'tha . system: The meter is adjusted simulta­ than CdS detector and .'retain low light level neously with the diaphragm control and so Jtie semsitivity even after use in !bright light. reflects the preset stop in its reading. When the I ,.) ~ e~~osure release is operated. the . lens is auto­ A relatively new developrTlent in the exposure rTlatically stopped down to the preset point meter field is the integrating or flash exposure before thC\) exposure is actually made.. Many meter. These were made practical for norml;J ',single .lens reflex cameras, are arranged so that use by thE)) miniaturization and low power req'iJire­ , either method can be used. ments of solid-state electronic modules, which (/ reduced the size of the unit from a laboratory Either rnethod . has 'th& idvantage that it instrument to a pocket meter. , compen~ates for bellows extension on close-up 1\ shots; for. variations in diaphragm calibration The unit senses any sudden increase in light i' from lens to lensi for variations in lens and measures both brightness" and duration, transmittance; and for filters placed. over. the even when the latter is only a few mjcrosec~ lens. "Either method eliminates the hyper­ onds. The, product of the two, which is toe total sensitivity to bright ligt'lt sources just outside the exposure, is then displayed on a meter. With , -:, field~Of-vic;lW of the lens, whiph' is "characteristic this type of meter, the photographer can make of' photocells external to the main lens. Both a flash lighting setup containing several differ­ , ;1 , through-the-Iens systems' are quite sensitive to ent sources· fired by slave units from a master I ''\' feed-back of stray light through the eyepiece of " flash lamp and) predetermine whether his expo­ i the" vi~wing system. The stop~down method is sure is correct or not, something that had not ,.1 . 'I more prone to' .trouple· since it is always working , previously been practical. Meters of this type with a lower light level at the sensor. . '.', ,':\ measure the reflected light received at the cam­ .".1 era from the full subject for the full duration of .:) , The through-the-Iens e~posure system normally the flash . u~es two or more photoes,Us, which are so" positlcmsd that each views a limited area of the Some othe.f'types of exposure 'sensing systems scene. Their relaJive effects on. the camera ex- are in use, such as photocells around, but Size, speed. color sensitivity. grain, contrast, singular packaging and pro­ posure are balan'ced. for the ·be.st over,all result. external to the lens, and photocells built into the ceSSing are all factors to be considered in Generally, the center portionof.thepicture area reflex mirror as part of the coating, which film selectiOn. . ha~'fmore effect on a~posure' than the outer reflects the light to the viewing screen. While borders have. there are some advantages and disadvantages ,q,":/ . "~'''10 each different system, all are capable of Anatoer type of through-the""ens system in use providing good results. Some are. more forgiving has ~.' single photocElIi positioned on the lens of one type of error' and some of another. A axis, «small distance away, from the film plane. little experience with aoy one of them will allow This "gives a. center-weighted exposure the photographer to learn their .. individual det~rmit'lation. The cell is retracted from its idiosyncrasies and obtain. consistent' exposures " ;' \ ,position aSlthe' shutter release is operated. under mapy conditions.

42

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,.t>, I FIL.M in the negative, becomes noticeable. With the Roll Film. This consists. of long strips of film •. ','", fast or medium sl:)eed' films, under any coi'ldition normally for eight to twelve exposures, backed other than ,)deal, a 50-line pair per .millimeter by a slightly wider strip of light-proof paper, f I resolution IS a re!asonable expectation. This sets marked with exposure numbers to provide the the maximum erllargement at five times. which proper spacing between frames, and rolled onto means a 12.5 x 18 cm (5 x 7 in) print from a a light-tight spool which can· be loaded into a 35 mm negative. before 'quality starts to drop, A camera in daylight. Film ~vailable for the use of the law enforce­ make 20 x 25 cm (8 x 10 in) .prints: large size 6 x 6 cm (2'1/4 x 2 1/4 in) negative .. under llIent photographer varies widely in size, speed. negatives. from :z;ero to three times; medium identical conditions will give a 28 x 28 cm Bulk Film. This consists of carefully slit widths of (Iolor,sensltivlty; grain. resolution. contrast. maxi­ size· negatives. from three to eight times; and (11 x 11 in) print. which means we can crop off film of various dimensions. similar to roll film but mum densjtyand sensitivity to handling. as well small size negatives, ,more than eight times. The part of the negative and still get a 20 x 25 em minus the backing paper'. Generally supplied iti as In how'it is packaged for different types of division between medium and' small negatives (8 x 10 in) print with gOOd detail. lengths of 100 feet or more in light-proof cameras, and' whether. it is processed by ,con- ... falls at a critical point hi the recording capability wrappings. It must be manually loaded into the ventionalphotogtaphic methods or is of the, of photographic material. The result is the re­ The guidelines given ~bove must not be taken camera or some form of cartridge or magazine. as hard and fE:lst numbers. seven times en· instant process type~ quirement for a major change in total photo­ A in total darkness. before it can be used. Bulk graphic technique. When the shift is made from largement frorn one negative may look good. film includes motion picture film, which is For this guide" we have basically considered medium to smalf size negatives. The dividing while the duplicate shot next to it on ~he roll normally on a flanged spool which is proof both, equipment and film as Qeing in three line between the two techniques is not abrupt or may look. very bad. Obviously, something against subdued light and is provided with general size categories: small, medium and rigid. but the personnel responsible for selecting .happened to make the two different. but deter­ sufficient extra film on the roll (generally about mining what it was and preventing it from large. Film siz~s 35 mm wide. and under f~" in equipment that wi" determine the picture size 10 feet) to serve as a leader and trailer to the small, category. Films from"', 35 mm to used for various purposes should be aware that happening again may be impossible tasks. The protect the main portion of the film from being. 90 mm fall ir,l the medium size category. Any the decision is not to Simply "make the' print generalities drawn will be found valid in fogged during the process of "loadingintQ a film larger than 90 mm has arbitrariiy' been larger." Small negatives can and do produce practice. They should be given proper considera­ 16 mm camera; . placed in the large category,_ In the 'small size excellent prints ,even larger than 20 x 25 cm tion in determining the film size that will form Film Cartridge. This is the standard packaging are found sub-miniature cameras and 35 mm (8 x 10 in). They do not do so as conSistently the foundation for photography in any law en­ for film for 35 mm still cameras. A length of cameras with picture sizes of 24 x 36 mm. In or with the same lack of care and attention to forcement operation. 35 mm wide. perforated motion picture film. suf­ the medium size category are found a collection detail at every stage in lighting. exposing. pro­ ficiently long for .20 or 36 exposures of of Cameras taking pictures 6 x 4.5 cm cessing and printing the final picture, as can be Packaging 24 x 36 mm size. is wound on a standard size , (2 1/4 x, 1 5/8). 6 x 6 cm (2 1/4 x 21/4 in), done with medium or large negatives. This is a spool, and inserted in a metal magazine 6)( 7 cm (2 1/4 x 2 3if4 in) and 6 x 8 cm fact of life due to the basic nature of the photo­ Film is packaged differently for use with. differ­ . provided with a v.. ~lvet lined slit through which (~, 1/4 x 3 1/4 in). plus a few odd sizes (mostly graphic. process. ' ent cameras. Six different types of packaging \ the end of the film is extend$d. The magazine instant process). In the large size are found are commonly encounfered. \ dimensions are standardized and the loaded 8 x 10.8 cm (3 1/4 x 4 1/4 in) (mostly instant Experience and tests have shown that a photo­ . .1 process). 10 x 12.5 cm (4 ~ 5 in) and graphic print will appear crisp and,sharp to the 20 x 25 cm (8 x 10 in) pictures; observer only unde ... certain c.I,'lilditions. One of thrJse conditions is the finenEj)~S of the detail it The 20 x 25 cm (8 x 10 in) print will be contains. Detail finer t~an ab!();ot 1/20 of a milli- considered the standard picture 'size toward . rn9",i (that is. 10 line' pairs par millimeter) will which all law enforcement photography is noti: .. contribute to its appa~'ent quality. If the aimed. This will be true for the majority of pic­ finest detail is coarser than this. the observer tures Intended for formal court presentation and can tell that the quality has been lowered. Slow .it is th~) preferred size for many oth6r purposes. and medium speed films can record well over It will not .batrue, however. for pictures from 100 line pairs per millimeter when used with specialized sY$tems used for making personnel ordinary lenses. and at apertures several stops identification . photos. for some fingerprint smaller than maximum. High speed films have photos. and for some surveillance pictures lower capabilities; even under ideal conditions, wherEI picture size may be deter~ined by how 80 line pairs per, miUimeter is seldom reached. much enlargmen~ the negative can stand. DMding the line pairs per millimeter in the nega­ tive by the required line pairs per millimeter in With. reference to their classification as largs. the print gives us the maximum number of times medium< and sm&!!, negatives Will require the the negatiye can be enlarged before the following ~~ amounts of· linear enlargement to deterioration In print quality, due to lack of detail

44 45

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" 1\ magazine is light-tight' in direct sunlight" The Film Pack. This is used instead of· sheet film befor~ grain becomes .apparent to toe e~e, that are sirnila,r to their visual appearance, but protruding' end ofthe!ifilm strip is fastened t(Hhe . when many pictures have to be made in rapid while a high-speed film may have its grain red objects will stili be muqh too. dark; camera takS'!UP spool, and the ll1m"-ttansferred . succession. A film pack consists of a stack of apparent to the. eye with no enlargement. The~ , Panchromatic. films tend to show "all, colors in rel­ to· this spool during picture taking. After expo­ thin-base sheet films loaded in a metal frame coarse-grain film has to be u!)ed only in large ative shades of ,gray that match their relative ' , sure; the, film must be m~nuallyrewound(back I,\, with opaque black paper over the ,top sheet and negatives or serious limitations on maximum brightness to the eye. The majority of black and , i into, the magazine befor~1 the camera can be between films. A long paper tab is fastened to acceptable enlargement must be accepted~ It is white film used in law enforcement today is l [,. <- .;; opened and the film'remo)led. the bottom of each sheet When the first tab is not likely to produce a good print from a 35 mm panchromatiC Ii and C:it Is best for general use. " .. t pulled"the safety cover is removed from ~ front camera, whose negative must be enlarged eight However, w~ere large amounts of one type of I the stack. After the front film of the stack is 1 ~. "'ristaritloadCartridge. This consists of two fUm or more times to get a. 20 x 25 cm (8 x 10 in) work are b~ing done, the use of one of the I magazines (on\~ for unexposed, one for exposed, its paper tab is pulled, transporting the picture. other types of film may offer advantages. !. film from the position in the front of the stack, ..." exposed film), cijnnecfed by a film gate or sper­ it emulsion facing the') lens, around the bottom Grain is a function of exposure and de~elop­ All manufacturers iSsue specification' sheets for I; tvre which guides and locates." the film. Since end of' ffie stack and into the back with the ment as well as of film type. In general, overex­ each of the films., which they manufacture. the film is already a,Uached to the take-up spool, ". ~' there is no film thr'eading or rewinding involved emulsion facing away· from the lens. A flat posure and underdevelopment tend to decrease These sheets list th~ film characteristics, give . ~, . graf~ size. Fine grain developers reduce grain correct processing times and formulas, and list I; in using the inst~nt load cartridge. The cartridge spring divider, originally pushing the entire stack is shaped so that It can only be inserted in the to the front of the film pack frame,' is now size, sometimes at some sacrifice of film speed. the type of subject for which the film is ~pecially between the exposed and unexposed sections, Excess soaking in processing solutions; and suited. . , [\! camera in ol)~ way. Inserting. it automatically adjusts the camera expoSl4re mechanism to the pressing the unexposed sheats forward to higher temperature processing solutions, It 1 proper spe$d setting for the type of film register with the front of the pack frame, The contribute to increased graininess. f,: contained in the cartridget When the last expo­ film~~~r~ then exposed in sequence. Film packs COLOR FILMS :r. Since filllls are available in a wide range. of ~' sure Is made and the film advanced to tl'/e elid, are highly convenient in the small sizes and t< provide a hirge exposure capacity in a very speeds, a medium-speed film is generally th~ I" the camera can be immediately opened and the The films so far considered have been the If small space. Both fully exposed and unexposed best choice for all around use. Higb-speed films ';' film removed without rewinding. Instant /qad car­ ,; 'are best reserved Jor those jobs where any pic­ normal black and white negative type. Color tridgesare available in three sizes: 126 size car­ packs can be placed in a film 'pack adapter in , ture is better than none and tests have shown films must alsb be considered. ' I t!Jdg~ti(for 29. x 32 mm picture size instant load daylight. The adapter is placed in the camera that medium-speed films produce.~ no picturf;!. I i cameras; 110 size cartridges for sub-miniature and used exactly like a sheet film holder. Pack Packaging. All color films are packaged in ,/ film must be made on a thin basei to al,low for The smaller the area of the negative to be used exactJy the same manner as are black and [, '. instant-I.oad cameras; a09' Super-8 mm motion for the print, the more careful one must be to picture camera cartridges of 50 feet. the sharp bend in the reversing openittiqn when white films. The selection of 'Sizes is more the tab is pulled. This makes pack film, in the minimize grain. Speed ratings rang€::! from ASA 8 limited and not all types of color film are avail­ 10 x 1,2.5 cm (4 x 5 in) and larger sizes, highly for slow process films, to P.SA 4000 for able in all of the common sizes. Some color neg­ Sheet Film. This is packaged i~ light-proof subject to film buckling, sometimes causing extremely fast surveillance films. ative materials are available in a very limited packages containing a specified \number of local out~of-1ocus patches in the negative. It shoUld be noted that the effective film speOd size range~ accurately cut sheets of., heavy baselrfilm. notch Increased cost per exposure (as compared to which can be obtained on any emulsion is sub· coded in the upper right hand corner of the sheet film) is another disadvantage that must be Film Speed. Color films in general are much ject to some control by the amount of dev.elop­ sheet (when faqjng the emulsion side and the considsred. slower in speed than black and white'films;' Like ment given and the type of developer used. film is vertical) for easy identification of film type black and white films, however, the 'fl.lstest color ; This variation, for a given emulsion, is normally and emulsion orientation. Individual sheets are films provide the poorest resolution and the llless than the variation between a medium manually removed from. the packing in total grainiest pictures. The rated spee~ of color films Film Speed I$peed film and high speed film. darkness. and loaded into individual sheet film I: will V'dry from abOut ASA 25 to about ASA 400. '" holders containing twtl sheets of "film. back to An important characteristic of film i~ film speed. Fidelity of color reproduction tends to decrease back, separated by a divider. The~:hoiders are This is a measure of how much light must be " Color Sensitivity as film' gpeed goes up and is always sacrificed closed with opaque slides, after whic~they can allowed to act on thE'i; film in order to repord a when any cofor film is' puslJed. Pushing be handled In full daylight, inssrted'jndividually pict~re."For a given I~"el of illumination 'on the A characteristic of all black and white films is (normally applied to reversal or positive color into view or press type Qameras and one slide subject and· a given lens aperture. the higher their varying sensitivity to light of\ different film only) involves changes in processing removed for exposuflS. The, slide is replaced in the film speed, the shorter the exposure colors. Film is availabh;f/in three majb~ types of procedures which result in higher effective film the .reverse position to indicate exposure and required. However, high speed in 4i1m can only color sensitivity: color blind or blue sensitive speed ratings, at, the. expense of more grain the holder either re1/ersed for exposure of the be obtained at a price: a very significant loss in film; orthochromatic or blue and green sensitive (often much more), pt)orer color rendition and second film or returned to the darkroom for pro­ the film's ability to record fine detail and a great film; and panchromatiC or blue-green-red (all­ loss of overall quality iin the transparency. It has j cessing. Sheet film is commeJnly found only in siz~. coldtf sensitive film. Blue sensitive films will value when film is known to have been \ increase in the grain Grain is a characteris­ ,L sizfas 6 x 8 cm (2 1/4 x 3 1/4 in), 8 x 10.8 em tic, overall mottled appearance in the emulsion sJ'~w objects that are bright red to the eye as underexpo~ one or at most two stops. It (3114 x 4114 in), 10)( 12.5cm (4 x 5 in), 12.5 x forming the photographic image. A fine-grain black in the print. Orthochromatic films will should .be used as ant emergency tool and not 18 cm (5 x 7 in), and 20 x 25. cm (8 x 10 in), film can have its image, enlarged many times show blue and green objects in shades of gray used consistently.

46

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:r

Types of Color, .EmUISic)ns. Color. films come in . Color Neg/itive Films. Color negative films are (1 the, form of 'positive or reversal emulsions and" -=similar in m~ny respects to positive color films: ",film holdersj1rastant'process film is available in expiration d~tesgiven on film and papar apply ... ~" cdlcr negative'"rr1uiSioris,'; AI.I ,color films are very they are multilayer in construction, start with '. roll¢, .prd:~:h.Jbing a' picture size 018 x 11· cm for storage at '.' fOOI11 temperature (not OVer 75 . complex, multiple layer emulsipns, ascomparad metallic silver images and arid with color dye .' (31/4 x 4}14 in), with rEding~i of ASA 200 oF) Deterioration is greatlyslo)Yedby storage at ···to the' simple one· to three layers found in black images. The' development process is carried (Type 42), ASA 3000 (Type 47), ASA 10,000 low. temJ)e~at~re(40 to 50 OF), as in a normal an(fwhite films '(an~i-halation sub-coating, silver only to the Roint where the negative image layer (Type 410), ,and high contrast ;'(oscilloscope refflg~rat~r~Flim so stored will show but slight halide emulsion, plain gelatin over-coating). is obtained: Conversion from silver image to .' recording). Film, packs prodUCing a picture size detefloratlon\ after several years of storage. Film"" 1 ! SOm'e black and;) white, films have only thE,' color 'image opcurs ·at\this point, but the colors of 8, x 11 cm ,(3 1/4 x 4 1/4 in) are available that has be~ln refrigerated, hdwever. should be essentialsilverhalid6' emulsion layer. in the conversion are different. They are f with rating~ of, ASA 75 (Type 105) and ASA allowed to remain at Joom temperature in the s." , complementary to the actlJal colorsot the 3000 '(Type 107). Single exposure packets are sealed container for about three hours before I"'" '1 image at· that point. A blue object becomes a available intne 10 x 12.5 em (4 x 5 in) size use. Exposure to high temperatures will cause :1 Positive Color Films. .AII currently used .color negative blue or yellow image. A green object with film speeds of ASA 50 (Type 55 'PIN), ASA rapid deterioration, particularly at temperature ".1 f!'~S are multilayer films. ~ith.a mi.nimum of becomes a negative green or red image. There 200 (Type 51),,_,~~~ 4.00. (TYPE! 52), and ASA above 90 OF., ~_~___ ==~~'==i~_=.j.",,;;,,~ •. ~_, ~_=~--==~~- ---="r - -:11 3000 (Type 57):-Types=rObc=and-55=Ptt'hife'lC~,~_e~=~~~"--~- -~ . three separate" light se!1sltlve emulSions (plus are ~everal advantages to the color negative. 1 necessary filteranc;J separation layer~). each of Film speeds tend to be higher for a given positive-negative variety which produce a con~-' '.,1 . '~_-1= which records one of the· three primary colors graininess and resolution. The negative proqess ventiorial black and white negative, plus a (for most emul$ions red, green and blUe). In any is morefprgiving of minor errors iriM>XpO~ure" positiv~, paper print. The negative may be II , emulsion, the image starts at the· surface and than is the reversal process, requir~d for discarded ,or cleared, washed. and dried by con- . ,> 'extendsdownwarct~:;;; through the layer in positives. Paper positive'prints are ma~e from ventional, 'pro,rcessing methods, after which it can p~op()rtion to the illumination at that point. color negatives by direct printing on negative be enlarged\Orprinted like any other negative. .~~ntern" slide transp~rency film is supplied in 0:; ••--- - ~ ".e 'Development converts the image into a varying color 'printing paper and the processing thickness of metallic silver, like a relief map procedure is simpler than the reversal procesl?~ rolls, ASA 200 (Type 146L) to make 8 )( 10. cm upside down, backed by a complementary layer ing procedure that must be followed when (3 1/4 x 4 in) lantem slides, and ASA 80.0 having the same contour of undeveloped' and making prints on positive color paper. Color neg­ (Type 46L) to I\\lake 8 xii cm still!igh~+sansitive silver emulsion uncjer it, the atives also make excellent black·· and white (31/4 x 4 1/4 in) lantern slides. , ~\ whole l11aking up the thic;:kness of the original prints, on a special panchromatic printing or emulsion layer. In all reversal emulsions,this enlarging paper. This is exposed and processed Polaroid instant proceJf filr:n is also available in metallic silver negative image layer is chemically in a '\,manner identiqa,1 to that for normal black color positive or '!Polabolor" form, each expo­ sure producing one pd~itive paper print. This. bleached or removed. The remaining (I and ':1 white printing' paper. Color negative complementary positive image is then .re~ " matetial wpuld seem, to have the best of both film has an ASA rating 'of 75. It is available in rolls (Type 48) prodUCing an image size of .. expose'd to light and developed to a' positive worlds.Unfortunlitely, the color rendition \~n image. In a blackaqd white , the general has been inferior to that obtained with 8 x 11 cm, (3 1/4 x 4 1/4 in); in film packs positive image is madf3 ins~nsitjve to light and .the reversal processes; (Type 88) size 8 x 8.5 cm (3 1/4x 3 3/8 in) and (Type'l 08) size 8 11 cm Ii washed. In color film, I~ is necessary to convert x i,', the positive silver iliu~ge into' ,.a colqr image As the proc,ess improves in overall quality, there (3. 1/4 x 4 1/4 in); in single exposure packets Film and cameras should never be left in, a car :, formed of, colored dyes. And, in the color is certain.to be a growing application in law .en­ (Type 58) size 10' x 12.5 cm (4 x 5 in);· and SX- parked in the ho~ sun, particularly in the glove reversal proQass, each of the three layers of the forc.ement photography for the color negfltive 70 which produces an image of 8 x 8 em cO!T'partmentor the trunk. Exposed film may film mus( be treated individually and converted with its built-in capability for good black,!, and ,(3 1/8 x 3 1/8 in). The instant process color i~eteriorate more rapidly than unexposed film, separately into differently colored dye images. white prints without the need for a copy nega­ film is not quite as "instant" as the black and ,snd color film may be more sensitive to high The. complexity of the process and necessity,Jor tive. white. The color requires 60 seconds for devel­ temper&tures than black and white film. strict control are evident. oping, but does not require cleaning and coating after development, as does the black and white. Instant Process Film (! ' •• Summary At the present time, Eastman Kodak manufac­ It is rather obvious at this point that no single In' positive color films, variations in the composi- " The PolarOid instant process black and. white tures a single instant process film, available ., film takes a picture, develops prints it and de~' type of film be best for all law enforcement tions of· the dyes and the compounds used to it, only in color, type PH 10. The picture area of will tasks. In most small departments two or three produce them' cause variations in the ",grain"· velops the print, in a single operation taking \. this film is 6 x9 cm (2 1/2 x 3 1/2 in). The size ,. of the dye and., in the sharpness and about 15 seconds. Instant proces¢'fUm .is film speed is ASA 1SO. types should" be adequate. A medium speed panchromatic, general purpose film which is resolution of the re.suitant· dye images. Higher packaged for use only in instant process cam­ . .~ speed emulsio.!1s stil.1 tend to produce coarser eras, in rolls, film packs! and single exposure available in all of the si:?:es that are used !!Should grained ifTlages. These are some of the packets that' fit a special developing holder that Storage be standardized as the major film and used ~jements that determine the varying characteris­ can be used with any 10 x 12.5 9m (4 x5 in) whenever possibie. This gives the individual pho­ tics between color fil~l'lS of different types. press 01' view camera which takes standard size Photographic materials-film, paper' and pro­ tographer the maximum amount of experience cessing solutions-deteriorate with age. the with one emulsion, and is the best way for him 48 49 _____ -----.------~------~~.-.-JJtl-.~--==~.~~~_~~---~~~II ....- ...... "",.,,, "

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. )?,~, " .. a., ' ". .." . '.' . r:;l. ir "",. : "~;,: },: .'.' .t(r'iearn . what. .. his' tilm )Vih/i. and .wUI .not. do. A Color versus black ~nd white should be dEl.cided . '. panc:hromaticproce$s~fype;!ilr:n. will be of great . qn the rE)quirementsof ~tiEf 'application. Color \. i::;,!,) value where the material to be photographed, 'photography is much more:eomplex lhsn black ,:;;! ha~ '~~rJ ,Iowc()"tra$t,~ych~$faded Rhoto- and white. For rnanfdepartments, use ofcolp,r :" ,q::,~:.',:\"ll: graphs'! andprintet:i n1llttElr, 'or primary m~ans. .that, '.. all:colpr . processing . will be ;~:1 monochrome, ·Ukesome ". fingerprin~s. Many contracted out. .Thi~ .means ,tbat proces!Jing lIG~TIl"G .... qu~lIity will probably be' held to morEHJoiform \ 1 other ,uses for the 'proce$s type of emulsjon will a- EQlSlPMENT " :x 1 be found. Proper' choice.-9Jj:Je'lalaj)erformulas .standard thElnwhen .done in~house (in~ny but .,.! '. '.<,':1 greatly ?J:9~c;lEins:';he~contr~st range that can be the . largest . departments where a major! effort 1\. j,J__ =-_-=-c-, ,,_-.!.WW'fea, particularly in ,the ~irection of reduced can be justified to achieve processing control). ~-=-__ ~~~~ c, contrast by using soft !l0rking d~velopers. While quality can become more uniform 'under these conditions, flexibility to cope with unusual i .. l There will also be requirements for an ,~xtremely situations wiJl be ~o.rrespondi~Qly lessened. It .. " ..:j high speedem&lsion for surveillance and

- \;: , {f Supplementary lighting problems can 1 ! usually be solved by the informed applica­ I tion of either an electronic flash, a photo ·1 , j. flash or flood lights. 0

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fixed amount of ,charge from the batteries for recharge the capacitor. Thisinakes for a great' every flash and uses it all. If more light is put saving in' battery ent:3rgy, so that many more out than is needed, the photographer has to flashes per set of batteries (or per charge on stop down the lens to obtain the correct expo­ the rechargeable ones) are· obtained. Pictures sure. The second, or automatic, type varies the can betaken more rapidly, since it ta~e$ less duration of the flash to suit the needs of the situ­ time to charge the capaCitor fully' when it starts ation. with a parti~1 charge.

The problem of providing supplementarY lighting is simple to design very efficient reflectors to The first 'automatic electronic flash lamps used The major advantage of the automatic~ unit is 1 I for taking law enforcement photographs ~as,,'" concentrate aI/ of the light where it' is needed in a quenching cirquit, controlled by a photocell that it greatly simplifies the problem of taking always been ,$ difficult one to solve. ~!1!1equip­ the fll:lld of the camera. sensot that measured the reflected light from pi9tur~d with flash illumination; exposure is auto­ :1 oInenl avaiiablEl today, the' solution is' getli/1g .. the s'lJbject. This type of circuit turns off the matically determined. This will be found much·simp!er.IbtEl!=tJJa~ic typ~s of sUPJ:?lemen­ Electronic flash lamps are rated for the amount flash lamp as soon as the correct amount of especially helpful when the· photographer is tarylighting are available: electronic "flash, of light they put out in several ways: in beam light has been put on the subject, but continues using both flash and existin~ illumination. I photoflash, and' floodlights. What they will and candlepower-seconds, a direct measure of the to drain the energy from the storage capacitor Balancing the two for a pleasing overall effect is will not do, and where they ~re of greatest ,use, .integrated output in light units; by the e.lects-ical . until it is completely discharged . simply .a matter of selecting the' desired aper­ will be considered. " input to the flash lamp' in watt-seconds; by the' ture setting of the flash lamp. chOOSing a lens guide m!,mber of the system when used -with film The latest type is the thyristor-controlled elec­ aperture 1 or 1-1/2 stops smaller than this (to The electronic flash lamp is the most conven­ of a stated ASA sPEled rating; or by total light tronic flash lamp. This is preset for the lens ap­ prevent the flash from completely overri~ing the ient method, and it will solve most lisilting outP4t in -seconds. The , erture to be used, in most cases with a choice existing light) and setting the camera shutter probleflls for' still pictur~ taking. The, electronic provi4e;Cf in a table accompanying the unit, is of two or more apertures. The flash unit is speed in the normal manner for the bright areas ,or repeatiQg flash gu~ is a relatively, simple the most meaningful to· the photographer. provided with a photocell sensor which of the picture. Other possibilities will' suggest ", device which has been available bot not widely Dividing the guide number' by the distance (in measures the amount of light reflected back to themselves. usedi" photography fof almost 40 years. One Ci feet) .frorn the flash lamp to the subject gives the camera from the subject. It starts measuring of' the many unglamorous beneficiaries of the the f-number required for correct exposure with as soon as the flash comes on and,as soon as The traditional source of supplementary illumina­ 1" SPlice ",program" it has developed into a a film of the stated ASA rating. Typical guide the light has totaled up to the correct exposure tion is the phot"flasl1lamp: a glass , similar compact, inexpensive,light-wei~ht, and very numbers will be in the range from '250 to 50 or for the stop selected, the thyristor turns the to an incandescent. lamp bulb, filled with a _""P-~P ,'''' powElrful light !.source which now "tells' itself more for color film with an ASA r~ting of 25. At flash off, saving the balance of the energy that measured amount of metal wire or shredded . \\ whatto do pholClgraphica"y.'" , ' a 3 m (10ft) distance, lens ~pertures ~iII be was stored in the capacitor. When the capacitor metal foil in an atmosphere of pure oxygen. A from fl2,5 to f/5.0. Convenient calculators are recharges, t>nly the actual amount of energy primer, which is fired by an, electrical fuse, In the electronic flash, a small battery provides often integral with the flash unit. used to take the picture is replaced, rather than ignites the wire or foil on command when the low voltage" direct ciJrrent 'electrical power, the whole' amount needec~l to completely shutter is operated. The foil burns with a brilliant which is fed into ,a storage tank or capacitor Electronic flash sources are compact, some 1\ ,~ ,I)';'. ,,,;~-.. over.s time period of 10 to 30 seconds,' until the smaller than 35 mOl cameras. They are light in qapacitor is fully charged. ,This power is weight, typically less than one pound, and have converted into light energy by! discharging the . a life, of thousands off/ashes. Three types of capacitor through a Xenon flash tube at the power sources are found: (1) Dry batterie~of' instant the came~~:shutte~~~~~T~~~~~ '.. the standard flas~light~1L1! in t!!~:M~or'·A'size. tube has.1the ability to velyz!~l~~~;~~'t~~.k~~~fglVe 100 flashes the electncal ene~gy etored by the capacitor Into in the higher powered units; more in the lower. an extremely irt!tense pulse of light (radlant (2) Rechargeable nickel-cadmium (Ni-Cad) energy), and compress the conversion into an battery packs of about the same size as the extrem~ly short time period. battery pack. The' Ni-Cad pack normally gives few~r flashes per charge but can The flash of light from the Xenon tube has be recharged hundreds of times. A charger many desirable cti~racteristics. It approximates recharges the batteries when it';s plugged into the color of dayligfit, so it works equally well the 115 Volt acline.(3) Converters tHat allow with black and white\ and with c%r film. The . operation directly from the ac power supply, duration of the light is so short (about 1/500 of thus saving batteries where line power is avail­ a secrind at the very longest, to as short as able. In some flash units, the battery charger 11100,000 of a second) that there is little serves also as a converter. danger of any subject or camera motion

~howing during the time the exposure is made. Two different types of electronic flash lamps are I Be'Os:use, of the small size of the Xenon tube, it now in use. The first, or manual, type takes a 53 52

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flaa.h of light lasting aboutq 1/25 of a second; allow the use of other ~Ifiash guns" designed for gets lost and more gets on the subject where it where no electrical power is available, particular­ Photoflash lamps are Often fired from "flash larger photoflash'.Oulbs, or electronic flash lamp is wanted. The average life of quartz-halogen ly if movies are required. guns." >"[hese are flashlight~type cases which units. Even' with/flash ,equipment that provides bulbs is much greater than that of photoflood ," >contain the battery for igniting the lamp, al1 more iIIuminati9fn, it m~y( still not be' possible to bulbs, on the order of 50 hours rather than two The law enforcement photographer will require efficient for eontrolling and directing illuminate the; entire sCene. When necessary, hours. Because of the limited life "of both, a standardized set-up of lights for personnel the lIght and a wire !nQ the flash-lamp to two people ,;.\Iorking \qg~ther can cover quite photoflood. and tungsten-halogen lamps, identification photographs, preferably in a fixed the synchronizing circuit in the camera so that large areas,j "painting" the entire scene with provision Is generall~1 -made to operate the IQcalion where lighting and camera can be left the flaf;lh goes off when the camera shutter is light. One person operates the camera on a lamps at a reduced voltage during the time ready to use at ~ moment's notice. fUlly open. tripoQ, sh,Jtter set on bulb, opening the shutter required to set up and focus the camera. The 1 If much physical evidence photography is to be momEJntf,irily on command. The other"using the , voltage is then increased to the operating value .' Electronic flash lamps fire instantly (within a few ,done, other than at the scene of the crime,a battery-powered "flashgun" unit and a supply of for the actual exposure. Lamp:: life ,is greatly microseconds) when their firing circvit is closed. much more complete lighting set-up with lights the lar~er size bulbs, or an electronic flash lamp, increased in this manner. I Photoflash lamps require an appreciable length selected from the standar~ units widely used by syst~(natically covers the entire scene, breaking of time after the firing circuit is closed before commercial photographers may be desirable. it up into areas and firing a properly directed Where any volume of photography is done the illumination reaches its maxjmum value. The which demands continuous light for setting up, This includes flood lights for providing an overall 1 light in each area, being careful to keep the iI-" > ! delay varies with the type of bulb, ranging from level of illumination, spotlights for emphaSizing luminationaway from himself. The technique is posing, or photographing subjects, either still or 5 to 20 milliseconds. With photoflash lamps, the , > texture or lighting deep recesses, ring lights $imple. easily mastered, and very adaptable. A movie, the law enforcement photographer will firing circuit must be closed before the shutter which fit around a lens and provide shadowless dozen bulbs or flashes from an electronic f1ash­ need tungsten-halogen or photoflood lamps as starts to open. Most camera synchronizing lamp can illuminate a large area. light sources. They are the most compact, illumination, and reflectors for' softening circuits have two settings for this purpose: "X" efficient and portable continuous light sources shadows. Since lighting requirements are for electronic flash where the firing circuit is , Most ~lress-type cameras are provided with available. They provide the largest amount of determined directly by the object to be phQto­ closed after the camera ~hutter is fully open; -,, some f,)rm of photoflas,h lighting unit. Separate light per watt of electrical input or per cubic inch graphed" it is probably best to start with a mini­ , "Mil where the firing circuit is closed -about 15 photoflash "guns" are' available in both press of total size, of any continuous light source avail­ mum selection and add to it as required. For to 20 milliseconds before the shutter is fully many law enforcement photographers, an elec­ and miniature types and can be adapted to any 'j! able. Fluorescent lamps are more .efficient but open. The correct settinginust be made for the camera provided with synchronizer contacts. All bulki~r, and may change the . tronic or photoflash lighting unit on the main type of illumination being used. currently available cameras are so provided. camera with a second similar unit for side The tungsten-halogen bulb wo~s· well at low 'lighting, a slave-switch to fire both of trie flashes The -- big -advantage- of'the photoflash> bulb for \ A number of years ago, the photoflood lamp voltages. This has made possi~le 'continuous together, pius two or three small tungsten­ the photographer who only occasionally needs came on the photographic scene and "cast light sources that provide a numb)Elf of hours of halogen or photofloods in diffuse reflectors will a few bulbs, but wants them ready to go without light" on many qf, the problems of both still and illumination from portable battery ~,packs. These "cover all of the lighting requirements for many prior preparation, is that the bulb has an motion ph::ture, ,photographers. This was a can be used for lighting small are~s in locations aSSignments. unlimited shelf life, and is '& convenient, ever­ simple low: ,volfage incandescent lamp which ready source. For the high volume flash user, was over-vc.,lted to produce a very large amount - the main advantage is that the photoflash bulb of light. It tlraded lamp life for light and' lasted is a compact source of much more(;light than about two hours in continuous operation. The can be obtliined from the electronic flash lamp. tungsten-hal,)gen (also known as quartz-iodine) In a s,maltamc)l,mt of space, enough lighting can >lamp has peliormed a similar revolution. It has be' stored to, properly illuminate fairly large '. provided even more light from the same amount - '\ outdoor areas, such as accident and crime of electricaL power than the photoflood. at a scenes. The guide numbers for photoflash bulbs that more nearly approaches used with ASA 25 color film are typically 40 to daylight, and with a constant color temperature 50 for even sm(:lll bulbs, such as the AG-1B, and light output over the full life of the lamp. and exceed 100 for the large "press" bulbs. The photoflood bulb is large and requires much ventilation and large reflectors. The tungsten­ Those who USe instant process or other cam­ " , halogen lamp is 'Very small and its filament tem ft en~s that are designed to use the smaller perature is higher than that of other lamps. photoflash bulbs will quickly find that it is not po~sible to fully illuminate a large area, such as the scene of a night time traffic accident, for in Since more of its electrical input goe$ to order to get all of the area of interest into the 'produce light", it actually produces less total, fiaid of view, it is necessary to stand. so far heat than the photoflood. Its small size makes it away from the subject that insufficient light easier to cool and lends itself to the design of reaches the scene. Adaptors are available to very efficient reflectors. Less of the bulb's light

54 55 , i

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FILTERS .AND OTHER ACCESSORIES

, ,: r I In addition to filters there are many photographic accessories available. They vary in size and importance and are de­ signed to solve the problems that different . situations can present.

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with the same. color as the background (yellow), FilL. TERSAND OTHER ACCESSORIES we. can increase' the contrast. A deep yellow or Blue Gretm Red a minus blue filter will normally lighten the yellowed papE!r, making it photograph like a clean white; a:nd· increase the contrast in the final picture. Or: we can go the opposite way and wite a filtet that will hold back the parts of the picture which should be dark .. For the, sepia Thel Une of accessorie~, ~vailable to the Jaw el"!;­ nanometers; u While this is the range of ink, which is reddish, we use. a minus red ,~:lter, forctemaht photographer is nearly endllas.s. The wavelengths visible to the human eye, both which appears green. This will make the ink m61~t important (filters, tripods. and copy stands) shorter and longer ones are of. importance in appear blacker, again increasing the contrast of will' be described in some detail. Other, lells the copy. im· photogra~hy, particularly those in the infrared Red portant accessories will. be listed to remind the region'between 780 and 900 nanometers. All reader.that such equipment is available. ' filters pass light of some wavelengths and Every photographer dOing document photogra­ absorb· or reflect light of other wavelengths. phy should have a selecflion of several· densities Filters' are relatively simple but very necessary Filters are deSignated by what thE1Y absorb or of filters in each of the major colors, red. yellow, different type of color film has its own filter re­ tools. Every law enforcement photographer· will transmit. A high-pass filter transmits all green 'tfmd blue (see table 5). Filter selection quirements for conversion; filters. for the same need a reasonabie Selection of them. wavelengths longer than a certain vE,ilue. A low­ can sometimes be made by visual inspection, general light conversion cannot necessarily be pass filter transmits all wavelengths below a but actual test E1xRPsures will be necessary to used with different makes of film. .Filters are of two cons~!~ctions: solid glass, given value. A neutral density filter tr~nsmits all tell fOr certain what the overall effect is . ground and polished, intd· Which the ~ecessary wavelengths equally. A minus filter (minus blue, A special series of CC filters is available to color was incorporated ~hen the glass was for instance) absorbs the wavelengths Color Compensating· Filters correct for small variations between the iIIumina- originally fused; and thl" sheets of gelatin corresponding t@ the indicated color (blue). All (v'tion for which a film was designed and that colored with dyes and cemented between filters! reflect or absorb some of the light that Color compensating f' 's are used in color pho­ which must be used. Thes,e filters can, for sheets of protective glass; Gelatin filters are not reac~es them, even at the wavelengths they tography. They are usad with color film which example, be used to remove the excess blue as commonly used as· formerly because of the pass, but they absorb a lot more 9f the irlcident has bean deSigned for use with one type of il­ light present in daylight on a hazy day. The greater variety of solid glass fnters w~ich is now energy in the ."avelengths they do' not pass. lumination, when it is desired to usa it with a dif­ filters are bluish or reddish in tint and very trans­ available. There are, however, many useful ferent type of illumination. A commonly parent, come in a wide variety of densities and flltars that are obtainable·' only in gelatin. The Filters are normally supplied in special screw-in encountered example is the salmon-eolored are also used in color printing and transparency photographer should be familiar with .both mounts that are deSigned to fit specific lenses. filter number 85A, used to allow tungsten light copying to achieve color fidelity in the final varieties, and also with the fact that plain gelatin "Series" ·csize filters are circular, metal rimmed balanced color film to be u~ed in r.faylight. Each . copy. films, in 2, 3 or 4 inch square sheets, can be filters· deSigned 'for general use. The standard obtained very inexpensively and in more, than sizes are series IV,V, VI, VII, and VIII. Adapter 100'. tYpes. Because of their extreme thinness, a rings' are available that allow one set of filters to gelatin filter can be used in front of or behind be used 00 a number of different size lenses. ·~able 5.' Illost lenses without correction in focus. With Adapter rings are held in place on the lens by GUIDE FOR solidi glass filters, the lens focus must be friction and are simply pushed onto the lens. ({readjusted when working at close distancea SELECTING Step-up rings are available to fit small lens fiLTERS FOR ; ; with the filter in fro,,,t of the lens and will always adapter rings .. to allow the use of larger filter MAXIMUM need adjustment if it is necessary to use the sizes, further increasing the interchangeability. CONTRAST filter behind the lens. Always focus the camera with the fUterin place, or test ~or accuracy of focus if the filter is too dark for visual focusing. Contrast filters I " F'ive different types of filters will be found useful Contrast filters, which are the type most fre­ in law ~mforcement work: contrast filters, color quently needed in law enforcement work, are correction filters (commonly called CC filters), used to increE4se the apparent contrast in a sub­ polarizing filters, haze filters and neutral density ject; An example of this' use is the copying oif a filters, Each has specific uses. badly yellowed document written in sepia ink that has faded. With normal films, the documc3nt The underlying principle of the optical filter is rel­ is reprodl!ced with very little contrast betwelen atively Simple. Visible light .is made up of energy the writing and the paper, and it may be of aI/ wavelengths between about 400 and 780 illegible. 'By taking the picture through a mter :1 59 58 ~~ :;~" , ! ...... ,..~'M"'I?1~~!I- n'1'PlfrrrCLG,,,r I _II' ~... 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\' , ,. Neutral Density flltiSrs reduced 'or eliminated entirely, depending on cal enlarger with no lamphouse. External lights how .sironJQty polarized:, the light is. ThE( use of are provid$,d to evenly iIIuminate.the, f~1I The neutral. densjty fllter;lnd the polarizing filter large polanzing fllters plaood over light sources baseboard of ahe stand. The Jeenlarger' part IS are two types of filter Which, have an important in conjunction with a filter at the lens gives . really a 10 x 12.5 cm (4 x 5 in) camera with a property hI common. They both 'affect all colors ,~Imost complete control of reflections. A long bellowS,groul1d glass, and a r~flex approximately the same, aod therefore have, no p~larizing filter ~Iways requires at least a ~ne focusing hood so the operator can look honzon­ prondunQE!d color. Neutral' dtmsity filters 'are stop exposure Increase, since it cuts out at tally'into the ground glass. imAtead of having to , " used Ito reduce the intenSity of 'all wavelengths least half the light it (eceives. climb a ladder or put the stand on the floor. " I, of light b)requal' amounts. They are marked in Similar units Cire available to which a press,

I " terms of ~')ptical density, units. An 0.3 neutrQl Haze Filters single lens reflex or other type of camera can I~ density (Nt')) filter tr~nslT1its 50, percent of the be attached. Adapter backs will make sheet film roll film, 35 mm cO/Olr film, and in!'jtant light reachlhg it; a ~.o NO filter transmits 10 The haze filter is eSpecially valuable in law en m percent of the inclc;fent light; and a 2.0 NO filter forcement work. It is a clear glass filter which pro~ess film available for use on the c~pier. \or , transmits 1 ~~rcent. The densities of two filters reproducing identification photos, fingerprint 1\ has no effect except to hold back the ultraviolet (;' cards or documents of any kind with a wide !: used togethel" must be added in order to get the wavelengths. In ali except extr~me distance ~' overall density of the combination. Thus,' two views, the effect of the filter on the picture is nil. range of sizes, or for any type of small object I' tI 0.3. filters have an NO of 0.6 and transmit 25 It does serve as an excellent meQhanical (macro) photography, the copy stand is both percsn~ of the incident light. NO filters are of' protector and "transparent lens cap" for the convenient and time saving compared to ~ value for use with the faster lenses which improvised set-ups. Process type lenses ate " can 'ens. Dust, dirt, scratches, and fingermarks get only be stoPPEld dOwn· to 1111 or f/16. When a on the inexpensive, easily replaced haze filter, availab~'a for tHe complete Elssembly. These are fast lens must bel used with a fast film in bright instead of the front lens element. Haze filters corrected 'for giving imagEis up to 20 times light and the camera shuttsr speed cannot '.ire available, anti-reflection coated, to" prevent actual size. prll3vent overexp"osure; adding an 0.3 NO flltElr ghosts when used facing strong light sources. reduces the IIg~it by one· stop, 0.6 NO by tw0 stops& Q.~ ND by three stops and so on. Miscellaneous Trlp~ds critically with a 10 power magnifier. If the tripod Neutral density filters are of two types: sofid is vibrating on any of the exposures, a, character­ The list of other accessories is endless. Special glass, ill whloh light is absorbed in the glass, No law enforcement photolgrapher can work istic pattern will show as the image of the Ught me~tion is made of shive units which can be and evaporated metal film" in'which m6st of tflle wifnout a tripod or some othl9r form of C6\mera moves on the~ilm. This will be different than the attached to individual electronic or phoruflash light that Is not transmi~ed is reflected. Tw'9 support. The tripod is the traditional, most increased image size caused by overexposure. lamp units. When areas must be photographed evaporated metal film nelJt"~! density filter~ readily available, and probably most convenient Many times it is a figure-eight type pattern, but with supplementary light, any number of flash should not be llsed together, because the\.:. s~pport. A tripod shOUld be tail enough to hold any sign of a snake-like path indicates units can be located at strategic points. WIlen densities do'not add linearly~ Multiple reflections \ tile camera comfortably at eye I!evel, and should excessive vibration at that shutter speed. the main flash at the camera is fired, all the between the filters will cause the density of the fold sm~II enough that it is not lto() cumbersome Thereafter, use much higher or lower speeds. slave units fire too, without any wire combination to be less than the $um of the two in the camera kit or squad calr. An adjustable The good tripod will be firm enough for the connections to the camera. With f;!iootronic densities, and can produce undesirable Uelevator" post in the centor will save a longest focus lens normally used, easy to flash at each unit, the firing is simultaneous with interference effects. tremendous amount of time setting up for the adjust. not too heavy, and will not pinch fingers. the main flash. With photoflash lamp units, the required perspective. A quick-h~leas.e plate for Make sure the tripo~ is adaptable to both hori- slaves will all fire together, but all will be Polarizing Filters the" t}amera is a great convenience when the , zontal and vertical positions with all cameras delayed from the main flash by about 20 camera is attached and 'i~mg~ed frequently. and lenses. milliseconds and the shutter speed must be .. The polarizing filtel' is quite different in its effect Tripods that vibrate excessively'are of little lengthened accordintjly• than thtP NO filter. It, too, absorbs all colors of value. Many do so, but ,can easily be identified. < ' A pan tilt head is a very necessary accessory light equally. But 'light has another property, Put a camera with a very long f(lcal length lens for use with a tripod. It permits the camera to be Focusing magnifiers and angle viewers have which is not directly visible to thE) eye: on ii'ie tripod. Outside at night, point the lens at pointed in any direction and then '9tked in occasional value. They are available for many polari~ation. Ught is 'partially polarized a street light a few blocks away. Take a picture pOSition. cameras. Many times. a long cable release or a whenever it /sreflected from a shiny $urface of the light at each shutter speed on the cam­ tripping device will be essential." such ",s window glass. A normal photograph of era, plus some time exposures, say 3,5 and·20 A cable release should always be used with " a window may show only the reflection. and seconds. Try not to overexpose, and use Copy Stands canlsra on a tripod to prevent hand vibration. If nothing behind the glass. Place a polarizing ,neutral density filters if necessary for the long This is one of the most Llsefulaccessories for you do not use haze filters on all your lenses, filter over the camera lens and rotate it. In most exposures. Focused sharply, the street light the smaller de~al1ment which cannot justify a the use of a lens brush or ear syringe "blower" instances, one position of the filter can be found should be no more than a speck, like a star, on separate copy eam~ra. A popular typ~ is bUi,lt to remove dust bc:Jfore attempting to clean a where the glass reflection will be greatly the negative. Examine the stree.tlight image very much like a 10 x 12.5 cm (4 x 5 In) vert,- lens will protect the lens against scratches. . 60.' 61

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