Digiscope applications for shorebird studies

PATRICK R. LEARY

1291 S 3rd Fernandina Beach, Florida, USA. p.r.leary@worldnet. att. net

Leary, P.R. 2004. Digiscopeapplications for shorebirdstudies. Wader Study Group Bull. 104: 34-38.

Digiscoping successfullymarries the conventional function of spotting scopes(or telescopes)with technologicallyadvanced digital camerasto producehigh quality imageswithout compromisingroutine ornithologicalprocedures, thus offering biologists, researchers, and the like a highly convenientand economic tool to document sightings and observations.This paper addressesfundamental aspectsof this hybrid technology,field applications,equipment criteria, trouble-shooting, image processing and provides an appendix of Internet sourcesfor more in-depthinformation.

INTRODUCTION engravedcodes or faded colour not readily evident in the field (Fig. 1). Furtherimages collected throughout the win- In 1999 when LaurencePoh of Malaysia discoveredthat he teringperiod also documented the progressionof moult and couldtake digitalimages of birdsthrough his spottingscope changesin plumagecoloration as springmigration neared. and subsequentlyshared this newsover the Internet,he gave Throughthe circulationof theseimages, another regional ornithologistsworldwide a revolutionarynew tool for docu- researcherexpressed a desireto documentPiping Ploversin mentingavian subjectsand behaviour.Soon dubbed "digi- his studyarea and I am currentlyengaged in systematically scoping",this hybrid technologyallows owners of spotting cataloguingbanded birds within hispopulation. On occasion, scopesand (certain) digital camerasto receivedual service the expediencyof digiscopinghas facilitated the documen- from both devices.By combininghigh power scopeswith tation of fleeting behaviour like the predator response camerasfeaturing internal optical and digital zoom lenses,it depictedin Fig. 2. is now possibleto obtainimages comparable in quality to In late winter, when Red Knotsreappeared, I resumedmy thoseformerly requiring a highlyexpensive arsenal of cum- populationsurveys, digiscoped flagged and banded birds and bersome,fragile and heavy telephotolenses and camerasas againtransmitted their imagesto distantresearchers. Given well as endlessquantities of costly film. recent declinesin rufa Red Knots visiting Delaware Bay, Searching for an economic and convenient means to researchersthere becamevery interestedin our sightingsof documentmy own sightingsof rare and bandedshorebirds SouthAmerican banded birds in NE Floridaand digiscoping in NE Florida, I recentlypurchased a Nikon Coolpix 990 for madeit possibleto shareobservations of markedbirds on a usewith my 82 mm Kowa scope.My timing was fortunate, daily basis.Remarkably, one image refuted a concurrent,but becausewithin daysof receivingthe ,a southbound clearly erroneoussighting of the samebird far to the north. flock of 1,500 Red Knots Calidris canutustufa stoppedover Throughthis expeditiousexchange many contactsbecame in a local inlet and,among them were a few bandedindividu- awareof the high value andfunction of digiscopingfor field als worthy of documentation. research(Fig. 3). My initial effortsto digiscopethese birds proved remark- In additionto its digiscopingdudes, the 'unattached'digital ably simpleand straightforward, as was the subsequent view- camerafunctions well to documentflock size,habitats and site ing andediting of collectedimages on my homePC. Another features,invertebrate prey, disturbancesand more. Given its significantbenefit of digital photographybecame manifest compactness,convenience, image storage capacities, ease of whenthe imageswere expeditiouslyand conveniently trans- applicationwith the spottingscope and eliminationof com- mittedvia the Internet.Within daysof theirarrival in Florida, mercialfilm processing,my digital camerahas proven to be PatriciaGonzalez in far-distantArgentina was ableto recog- a highlyversatile, invaluable and economical research tool. nize and identify birds shehad bandedthere and the images documented Florida's first record of South American banded NECESSARY EQUIPMENT Red Knots. In subsequentmonths, digiscoping facilitated the docu- A broad range of scopesand are employed for mentationof otherbanded birds in winteringpopulations of digiscoping,but higherquality scopes and cameras produce PipingPlovers Charadrius melodus and Semipalmated Plov- superiorimages. Although an inexpensivespotting scope ers Ch. semipalmatusand, like the Red Knot images,many coupledto an economicalcamera may be functional, the of thesephotos were conveyedto biologistsand researchers resultantimages will not compareto thosetaken with better acrossNorth America to supporttheir studiesand resolve equipment.However: in comparisonto conventionalfilm discrepanciesin band codesor identification. The latter photographythat demandsa camerabody and a multitudeof function has been especiallyvaluable to differentiate and expensivetelephoto lenses, digiscoping simply requires the documentsimilarly bandedbirds within the sameregional singlepurchase of a high qualitycamera. (A PC with appli- populationor migratoryflock. In a few cases,the high reso- cable softwareis alsorequired to view, edit, process,store, lution and magnification of band images has revealed copy and transmitimages.)

Bulletin 104 August 2004 34 Leary: Digiscope applicationsfor shorebird studies 35

Spotting scope features Digital cameras

Two basic scopefeatures are of greatestrelevance for digi- For digiscopingapplications the quintessentialprerequisite scopeapplications. Because increased optical magnification of all serviceablecameras is internal focusing and zoom requiresgreater light transmission,scopes with largerobjec- magnification.Because they meetthis essentialrequirement tive lenses(-80 mm) are more serviceablefor digiscoping and provide other highly desirable features, the Nikon thensmaller (60 mm) scopes.Most contemporarymodels are Coolpix900 or 4500 seriesof digitalcameras have long been available with either straight-throughor angled favouredby digiscopers.The split,rotating body andlens of alignments.Straight-through is the mostconvenient for typi- thesecameras is particularly beneficial since it facilitates cal shorebirdapplications since it facilitatesthe timely loca- convenientcoupling while allowing full view of the LCD tion, centringand focusingof the subject;attachment of the screenand ready accessto all essentialcontrols. However, camera;and subsequentimage taking. The singleadvantage a variety of digital cameramakes and modelsare currently of angledeyepieces applies when digiscopingbirds or sub- employedfor digiscopingand, as technologyadvances, new jects well above the horizonthat requiresusers of straight- modelscontinuously appear in the market.(See Appendix for throughscopes to crouchwell below their tripodsto obtain Internet sitesoffering lists of scopeand cameramakes and similar views. Given the foregoing, potential digiscopers modelscurrently employed by individual digiscopers.) must consider their predominantmethod of observation/ It shouldbe notedthat for digiscopingapplications, the perspectiveand selecteyepiece alignment accordingly. photographeruses the camera's large LCD screenrather then Becauseof their versatility,many people use multi-power the viewfinder.Although the LCD imageis identicalto that zoom and these are readily applied for digi- renderedin the scope'seyepiece, it will be somewhatdim- scoping.When combinedwith the internaloptical and digital mer and less sharp.Furthermore, bright sunlight tends to magnificationof contemporarycameras, some truly remark- washout the LCD image, but sufficientclarity is (usually) able, long-range imageshave been made. However, such retainedto permit oneto centreand zoom on a subjectprior imagingis impracticalunder typical field conditionbecause to tripping the shutterand often one's headwearprovides high power photographydemands extreme steadinessof sufficient shadeto view the screen (see Accessories). gear,stillness of subjectand ideal light andatmospheric con- Virtually all digital cameras are loaded with a mind- ditions. bogglingarray of functionsand options,but little time or I have experimentedwith a variable zoom (20-60x) and experienceis requiredto masterroutine procedures. Perhaps a fixed power(32x wide-angle)eyepiece with the latterprov- the functionof mostconcern to digiscopersis the selection ing to be more functionalfor digiscoping.The improvised of automaticvs. manualmode of operation.In my experi- joining of two highpower optical devices is inherentlyprob- ence,photographing both roostingand foraging shorebirds, lematic and the fewer distractionsthe greaterthe chanceof the automaticmode serves well. Digiscopingis highly prob- obtaininga good image. Increasedeyepiece magnification lematic and the more adjustmentsrequired in the field the alsoreduces the field of view (making it difficult to locate a higherthe likelihoodof failure or missedopportunities. As subjectin the camera's LCD (Liquid CrystalDisplay), exac- with conventional ,superior results are best erbatescamera shake (blurring the image) andreduces light attainedin good light (preferably with the sun behind the transmissionto the camera(contributing to and camera)in close-proximityto the subjectand with camera slowershutter speeds and underexposure). andlens held motionless.Occasionally, insufficient light for The best camerasfor digiscopingoffer a range of inter- automaticoperation has compelledme to switchto manual nal opticaland digital magnificationthat, to a large extent, modeand I havemade a few acceptableimages in this way. compensatesfor any reductionin eyepieceversatility and This experiencesuggests that digiscopersin higherlati- magnification. tudesor in less sunnyclimates might obtain better results The diameterof a scope's eyepiecewill directlyaffect its usingone or moreof the manualoperation modes. Given the mechanicalconnection to a digital cameraand the better the multiplicityof optionstypically provided by moderndigital diameterof scopeand camera match, the fewer the problems cameras,most digiscopers should have little difficulty deter- of joining the two (seeAccessories below). mining which modesserve best for their mosttypical envi- ronmental conditions. Scope mounts and tripods Camera settings All formsof high powerphotography are adverselyimpacted by tremor or camera shake that result in blurred images. The camerasettings of mostconcern to digiscopersinclude: Thereforeit is importantto use a firm support. imagequality (file size),metering, operational and program A 'liquid' tripodhead that offers smooth vertical and hori- modes,sleep cycle period and ISO equivalent.Various, inter- zontalmovement is idealfor digiscopingand, when mounted active, combinations of these selections will determine im- on a conventional with telescopic legs, is quite portantaspects of imagingand the interval requiredto store adequate.Light-weight tripods are lessdesirable and heavy- data on the memory chip, relative size of imagescollected, duty models,though better at keepingthe equipmentsteady, data processedfrom the field of view and so forth. To a are burdensometo carry in the field. Conventional,pointed degreethese are discretionaryand subjectivechoices, but in tripod feet servewell on mud and sandsubstrates and allow my experience,the following settingsserve well: the legs to be pushedinto the groundto reducewind vibra- tion and provide a more stableplatform.

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Fig. 1. Piping Plover with faded bicoloured band engraved with Fig. 2. Pipingplover in "hunkered"defensive posture on open beach alpha-numeric code (photo taken with 82 mm Kowa scope and watchingpredator high aloft (photo taken with 82 mm Kowa scope 32Wx eyepiece coupled to Nikon Coolpix 990 - full optical zoom). and 32Wx eyepiece coupled to Nikon Coolpix 990 - full optical zoom). 1. Operationalmode: AF continuous(permanent autofocus - this minimizes focus time) mentoffers a hostof adverseconditions that conspire to frus- 2. Image quality: Fine (combinedwith next) trate the photographerand spoil one's images. 3. Image size: 3:2 (sameaspect as 35 mm film) In my experience, the sharpestresolution digiscope 4. Programmode: P (leastadjustments required) imagesare obtainedwith a fixed magnification,mid-range, 5. :Matrix (generaluse applications) scopeeyepiece (such as 30x) and within the optical zoom 6. ISO: AF equivalentto 100 ISO rangeof the camera.Digital zoomis highlyproblematic and typically producesgrainy, unsatisfactoryimages. On occa- For a protractedperiod I neverexceeded the file capacityof sion, I have used this function to document band details or a 64MB memory chip and the 8x speed seemed inaccessiblesubjects at verylong range, but the clarity of the adequatefor my needs.However, a singularexperience with imageis neververy good.The unavoidablereality is that,as a satiatedcard convincedme to upgradeto 128 MB and 12x magnificationincreases, less movement is requiredto distort speed.Given their diminutivesize and ease of replacement, the image.In somecircumstances, digiscopers might experi- sparecards are convenientlytransported into the field for ment with scopesand camerasremoved from tripodsand expandedcapacity. The same applies to batteries;conse- "nestled"in a firm cushionor similarly paddedreceptacle quently,I endeavourto beginevery outing with fully charged placedon the groundor on a wall or rock to reduceor elimi- batteriesin the cameraand a completeset of sparescarried nate vibration. Cliff-side locations or elevated dikes and alongfor extra security. bermsmight also provide suchopportunities and be more conduciveto photographyin adverseconditions. Optical zoom vs Digital Accessories Most digital cameraspossess optical lenses equal in resolu- tion to those in spottingscopes. Theoretically, an 80 mm As digiscopinghas grown in popularity and expandedin scopefitted with a 20-60x zoomeyepiece coupled to a dig- application,several accessories have been manufacturedto ital camerawith 3x opticalzoom and 4x digital zoom should addressvarious problems inherent with the hybrid technol- produceextraordinary images. However, the naturalenviron- ogy. Chief amongst these are mechanical connectorsto facilitatethe criticaljoining of camerato scopeand consum- ersshould have no difficulty obtainingthe appropriate-sized connectorfor their equipment.Because all commercialcon- nectorsare rigidly constructedthey may be less suitablefor ornithologicalapplications that require the camerato be con- nectedto the scopevery quickly. Conversely,improvised connectors, like those fabricated from film canisters, dust caps,etc. are lesscumbersome and often more convenientfor alternatingbetween conventional scope mode and digiscope mode. However, they may requirea steadierhand to mini- mize camerashake. When fabricatingthese, some experi- mentation is required to determine the optimum distance betweenthe camera and eyepiece.My dust cap connector providesa glass-to-glassseparation of 12 mm, but this will Fig. 3. Uniquely colour-bandedand flagged Argentinean Red Knot vary betweencameras and eyepieces.A too spaciousgap recorded May 2004 in NE Florida (photo taken with 82 mm Kowa betweencamera and scopeis likely to exacerbatevignetting scope and 32Wx eyepiece coupled to Nikon Coolpix 990 - full andcontribute to undesirablemovement between all compo- optical zoom). nents(see Appendix).

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Devices to shade (hood) the sensitive LCD screensare alsoavailable, but theircareless employment carries the risk of inadvertentlyoverheating the screenif the hood's view- ing lensis directedtoward the sun.This risk might be elimi- nated by removal of the 2-3x lens, but this practically negatesits designedfunction. Hoods are worthy of consid- erationfor certaindigiscope applications since they accom- modate focus adjustmentsto the scopewhile the camera remains attached. Otherwise, a shifting subjectrequires removal of the camera, relocation and refocusingof the scope,and re-attachmentof the camera - a fundamental problemof digiscopingand a sourceof greatfrustration. Effortsto reduceor minimizecamera shake or equipment vibration have lead to the developmentof extensionrods, mountingplates and similar attachmentsto secureor brace the camera/scopeconnection. Some are designed with clever pivotsto swingthe camera on andoff the eyepiecefor alter- native service,but their employmentrequires one to become Fig. 4. Author's digiscopeequipment showing modified dust cap connector on slipped onto scope eyepiece (rubber to accustomedto the bulk of a digital cameraadjoining the rubber). eyepieceduring routine observations and the alignmentof all componentsis critical. Frequentexposure to wind resistancewould also seemto precludetheir usefor many field applications.Because of 1. Firmly settlethe tripod in the substrate. harsh marine conditions,I prefer to store my camera in a 2. Locate,centre and sharply focus the subjectin the scope. securepouch on my hip anddeploy it only whennecessary. 3. Turn the cameraon (typically requiringa few seconds) I cannot foresee how such cumbersome devices would andcarefully slip it ontothe eyepiece,taking care not to expeditethe simplejoining processI currentlyemploy and moveor shift the scope. digiscopingpioneer and innovator,Laurence Poh expresses 4. View andcompose subject in the LCD screen.Occasion- a similar view on his personalwebsite (Fig. 4). ally, the imagewill be surroundedby a black "halo",but Also to be consideredis a rare but significant hazard this effect rapidly diminisheswhen you: associatedwith the semi-permanentjoining of cameraand 5. opticallyzoom into the subject,stop where desired, hold scopeand subsequentexposure to direct sunlight.As with the camerasteady and depressthe shutterbutton. LCD hoods,there is at leastone accountof seriousdamage 6. If the subjectremains stationary, take several images in to a camera'sshutter from directsunlight focused through the quick succession. scopewhile it was inadvertentlypointed at the sun.Appar- 7. Removecamera, adjust scope focus and repeatsteps 4-6. ently, thisoccurred during transport when the ownercarded hisequipment over his shoulder with thescope pointing sky- Trouble shooting ward! Shouldthe subjectmove out of view in the LCD, leave DIGISCOPING IN PRACTISE the camera switchedon, removeit from the scopeand repeatsteps 1-5. If this processcontinues without suc- Digiscoperscan be separatedinto two generalgroups: seri- cess, remove the camera and turn if off until the next ous photographersthat securelyjoin their equipmentand availableopportunity. (Some cameras will cycle off or accessoriesin advance;and biologists,researchers, birders 'lock up' whenleft on for protractedperiods and, in such and the like who usetheir unencumberedscopes for routine cases,they mustbe turnedoff and reactivatedbefore an observationsand attachtheir camerason a when-required image can be taken.) basis.I includemyself in the lattercategory and my experi- encesexclusively reflect this circumstance. . For moving subjects,endeavour to track them at a right Typical digiscopeopportunities blend seamlesslywith anglewhere the focuswill remainrelatively constant and routinefield activities.The observeris usuallyin closeprox- severalexposures might be takenin successionas the bird imity to his subjectand often little effort is requiredto stalk progresses(a commonsituation along shorelines). into a more favourableposition. Once a subjecthas been selected,the scopeand the tripod's central column should be . Vignetting(the mostcommon problem inherent to digi- lowered and well securedwith the head adjustmentknobs scoping)derives from discrepanciesin the relative con- tight but with someminor movement possible. If additional vergentpoints of light passingthrough the cameralens stalkingis anticipated,hold the camera in onehand (lens cap andscope. If opticalzooming does not eliminat6 the halo removed)and carry the tripodwith the other.Alternatively, effect,some adjustment of theconnector may be required lower the tripodto kneelinglevel andapproach in like man- and/or the camerasettings require adjustment. Insuffi- ner with the scopeat a comfortableheight and positionto cientambient light may requireswitching from AF to M- accommodatedigiscoping. REC mode, opening a Pandora's box of options with Once optimaldistance to the subjectis attained: variableconsequences. Rather then progressing by trial

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anderror in the field and missingvaluable opportunities dutiesdemand special attention and care. The wise approach one is advisedto consultthe cameramanual/guide and is to alwaysclean lens surfaces with a fine-hairedbrush prior experimentat home to becomewell familiar with the to removing film depositswith an optically safe cloth. many adjustmentsand their potential applications in Most moderntripods are constructedof lightweight alu- varyingfield conditions(see Appendix). minium or alloys that are resistantto corrosion.However, other components and hardware may not possesssuch . Imagequality and quantity. Fortunately, digital technol- attributes. To ensure trouble free function, one should rou- ogyaccommodates the expedientof collectingnumerous tinely spray down and lubricate all joints and adjustment imagesthat are economicalto store,process and archive. knobsfollowing every applicationin marineenvironments. Digital cameraspermit the immediateretrieval, review Following thesesimple but essentialpractices will signifi- anddiscarding of undesirableimages. In practice,ambi- cantly reduceundesirable mishaps. ent light in the field seldompermits satisfactory evalua- tion of images via the LCD screen.Regardless of an Image processing and storage image's apparentquality in the camera screen,one is betterserved to collect a seriesof imagesof one subject Although a camera's playback feature permits immediate andreserve analysis via processingsoftware on a PC. Per- view of a collectedimage, the absolutevalue of an image sonalexperience suggests that 10-12 imagesper subject cannot be determined until it is loaded and reviewed on a PC is typicallyrequired to produceone acceptable image and via an appropriatesoftware program. Even the most basic evengreater quantities may be desiredwhen digiscoping programsallow for enlargementof the image where any highly animatedsubjects. flaws or deficienciesreadily becomeapparent. Various versionsof Adobe Photoshopoffer a multitude Practitionersare advisedto collectimages in abundanceand of adjustments,manipulations and specialeffects. The most frequentlycheck scope focus and continuously refine adjust- useful applications permit fundamental adjustments to mentsto obtain optimum image quality. Seemingly sharp sharpenand enhancethe original image through light and imagesprojected in the tiny LCD screencan prove disap- contrastsettings and reduction of file size for Internettrans- pointingwhen viewedat largerscale on a PC. Even the most missionto colleaguesand associates.To a degree,most over- sophisticatedimaging software cannot make a silk purseout and under-exposed images can be salvaged, but little of a sow'sear, consequently,endeavour to collectthe high- improvementis possiblewith poorly focusedimages. Crop- est qualityraw files for later processing. ping can be an effective tool to eliminate irrelevant material and reduce file size for archiving and email transmission. Equipment maintenance Processedimages can be storedon a PC hard drive, but given their unreliability,one is well advisedto obtain a CD Regardlessof the quality of one'sequipment, it is essential or DVD burner and save all valued images on disk. Such thatall lensesexposed to the elementsbe well maintainedfor devicesgreatly facilitate the copyingand sharingof images optimumimaging. Consequently, digiscopers must be ever andtheir dispatchto distantcontacts. Digital technologyalso vigilant for the subtlebut obstructingfilms that accumulate accommodatesthe printingof imagesonto conventional pho- on all glasssurfaces and, because of the ubiquitouspresence tographicpaper for exhibits,posters and the like. of fine, abrasive, sand in marine environments, cleaning

APPENDIX

It is helpfulto recognizethat digiscoping has many devotees and some sources are more appropriate for professionalphotog- raphyas opposed to practicalfield application.Although all practitionersmay strivefor idealimage production, professional photographydemands greater refinement of gearand technique than is practicablein typicalfield conditions.A recentGoogle searchrevealed more than twenty pagesof digiscopesites. www.md.ucl.ac.be/peca/test/a.html (multiple topicsand links) www.shortcourses.com/now/digiscoping/digiscope.htm(multiple topics and links) www.digiscope.co.uk/ www.digiscopingukbirds.homestead.com www.laurencepoh.com/(Digiscoping'spioneer but out-dated- seenext) www.angelfire.com/pe2/digiscoping/index.htm(Update on Laurence Poh's equipment) http://kotisivu.mtv3.fi/mr/ds/ds_combination.htm(Index of digiscopersand equipment)

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