Definition of Terms
Forensic photography sometimes referred to as forensic imaging or crime scene photography is the art of producing an accurate reproduction of a crime scene or an accident scene using photography for the benefit of a court or to aid in an investigation.
It is part of the process of evidence collecting. It provides investigators with photos of victims, places and items involved in the crime. Pictures of accidents show broken machinery, or a car crash, and so on.
Crime scene photography is a branch of the field of photography which is focused on taking accurate photographs of crime scenes and criminal evidence, so that these photographs can be used in the investigation of crimes and in the prosecution of criminal activity.
ACETIC ACID – – A relatively mild acid used, in highly diluted form, as
the rinse bath (shortstop) which follows the developer in the normal film and paper developing processes. The acid in vinegar.
ADAPTER RINGS – – Narrow metal rings, threaded on the outside to
fit most popular lens, and threaded on the inside to accept accessories of other than normal lens diameter. Step-up rings adapt a lens for use with larger-than-normal accessories; step-down rings permit the use of slightly smaller accessories than the lens will normally accept.
ADJECTABLE CAMERA – – A camera with manually adjustable
distance settings, lens opening, and/or shutter speeds.
AGITATION – – The process of stirring, swirling, or otherwise causing
a liquid to move freely over the surface of film or paper during processing. Agitation helps to speed and achieve even development and prevent spotting or staining.
ANGLE OF VIEW – – The portion of scene that is covered through a
camera lens. The width of this wedge-shaped portion is determined by the focal length of the lens. A wide-angle (short-focal-length) lens includes more of the scene – – a wider angle of view – – than does a normal (normal-focal-length) or telephoto (long-focal-length) lens. APERTURE – – The opening in a diaphragm of a lens through which
light passes, expressed as a fraction of the focal length. The f/number.
APERTURE PRIORITY – – A camera feature that lets you select the
desired aperture, and the camera sets the shutter speed for proper exposure. When you change the aperture or when the light level changes, the shutter speed changes accordingly.
AUTOFOCUS – – The camera focuses automatically on the subject in
the center of the viewfinder when you press the shutter release.
AUTOMATIC EXPOSURE (AE) – – A system whereby the camera
selects and sets an exposure based on prevailing conditions without intervention by the photographer.
ARTIFICIAL LIGHT – – Any light other than produced by the nature
(sun, moon, stars, phosphorescence, etc). Electric lights are the principal artificial light source in photography.
AVAILABLE LIGHT – – The light condition which the photographer
finds existing at the subject position. The term usually implies an indoor or nighttime light condition of low intensity requiring fast film, large lens aperture, and slow shutter speed.
AVAILABLE LIGHT PHOTOGRAPH – – Photography without
supplementary illumination even under poor lighting conditions.
BB – – (BULB) – – A marked setting on most shutters which permits the
shutter to be held open for an indefinite period by continued pressure on the shutter release.
BACK – – That portion of a camera which contains the film;
specifically, the complete assembly attached to the rear standard view camera (and usually removable) which includes the focusing screen, and which accepts the film holders.
BACK LIGHT – – Illumination from a source beyond the subject, as
seen from the camera position, which tends to silhouette the subject, also called Back Lighting. BASE – – The transparent sheet material, usually acetate or polyester, upon which film emulsion is coated.
BASEBOARD – – The large, flat board, usually plywood, to which the enlarger column is attached, and on which the enlarger easel is normally placed.
BASE FOG – – Any uniform fog produced when an unexposed emulsion is developed.
BASE-PLUS-FOG-DENSITY – – The density of an unexposed area of a developed film (negative or positive).
BELLOWS – – The center section of a view camera which connects the front and back standards. The bellows is usually made of leather, cloth, or plastic, is accordion-pleated for flexibility and is, of course, light tight.
BELLOWS EXTENSION – – A term often used to refer either to the total bellows length or to the additional extension of the bellows (beyond that required for infinity focus) necessary for focusing at close subject distances.
BELLOWS EXTENSION FACTOR – – A number (multiplier) indicating the exposure increase required for correct exposure.
BETWEEN-THE-LENS SHUTTER – – A shutter designed to operate in a space between the elements of the lens.
BLIND – – An emulsion not sensitive to certain colors; color blind.
BLUE-SENSITIVE – – The sensitivity of an ordinary silver emulsion; red and green blind.
BOUNCE FLASH – – Directing light from a flash gun toward a ceiling, wall or other large reflecting surface to obtain the contrast softening effect of a diffused light source spread over a larger area of the subject.
BOUNCE LIGHT – – Light reflected onto the subject from surrounding surfaces rather than directly on the subject. BRACKET – – To make a number of exposures (some greater and some less than one considered to be normal) in addition to the "normal" one, with the intent of getting one near-perfect exposure.
BURNING-IN -- The process of allowing some relatively small image area to receive more than the normal exposure by shielding most of the printing paper surface from the light.
BURNED-OUT – – Describes an area of the print image in which highlight detail has not been recorded, usually because of severe overexposure of the negative.
CABLE RELEASE – – A flexible outer casing containing a stiff wire which can be attached to the shutter release on a camera. Depressing the plunger at the end of the wire release the shutter while minimizing risk of camera movement during exposure.
CAMERA MOVEMENTS – – Adjustments typically provided on technical and view camera to (1) enable the optical axis of the lens to be displaced relative to the center of the image while keeping the axis perpendicular to the image plane. (2) Position the lens plane and image plane at an angle to each other (swings and tilts). These adjustments may be provided as a swing front lens panel or a hinged camera back (swing back) or both. They are used for control of perspective and sharpness distribution in the image plane.
CHEMICAL FOG – – Fog on negatives or prints appearing, during development, in the unexposed areas.
CLEAR – – The appearance of a negative after the fixing bath has removed all visible traces of undeveloped silver halide.
CLEARING TIME – – The length of time required to clear a negative. It depends on the strength, temperature, and agitation of the fixing bath and the kind of emulsion being used.
CLOSE-UP – – Photograph made of an object to show greater detail.
A photograph made with a reproduction ratio greater than 1:10.
CLOSE-UP LENS – – A positive supplementary lens which, when placed over a camera lens, shortens its focal length and thereby permits closer-than- normal focusing. CLOSE-UP PHOTOGRAPHY – The techniques and practice of using supplementary lenses, extension tubes, bellows units, etc. to take pictures at closer ranges than the normal focusing adjustment of an ordinary hand-camera will allow. Refers to image magnification ratios of up to perhaps, 2x, and therefore overlaps "Photomacrography".
COLOR BLANCE – The ability of a film to reproduce the colors of a scene. Color films are balanced in manufacture for exposure to light of a certain color quality; daylight, tungsten, etc. Color balance also refers to the reproduction of colors in color prints, which can be altered during the printing process.
COLORBLIND – Descriptive of the partial or total inability to recognize or distinguish chromatic emulsion is sensitive only to blue, violet, and ultraviolet light.
COLOR HEAD – An enlarger light source containing adjustable dichroic filters which can be set to provide light of any color for color printing.
COLOR TEMPERATURE – A numerical rating given to the color qualities of a light source. Expressed in degrees Kelvin. The lower the color temperature, the greater the ratio of yellow/red light. Daylight is considered to be 5000 – 5500 degrees Kelvin.
COMPEMEMTARY COLORS – Any two colors in the subtractive system which, when mixed in the proper proportion, produce black or dark neutral gray. In the additive system, any two colors whose mixture results in white light.
CONCAVE – Hollowed out. The side of spherical surface seen from the center of the sphere.
CONDENSER ENLARGER – An enlarger with sharp, undiffused light that produces high contrast and high definition in a print. Scratches and blemishes in the negative are emphasized.
CONTACT PAPER – Relatively slow development paper for making positives by contact printing.
CONTACT PRINTING – A method of printing in which the negative is placed in contact with the printing paper, emulsion to emulsion, and held in that position in a printing frame. The exposure is made by exposing the frame to raw light so that the paper emulsion is exposed by light passing through the negative densities.
CONTINUOUS TONE – Describes an image containing a gradation of grays as well as black and white extremes.
CONTRAST – The difference in tones from the lightest to the darkest areas of negatives and positives.
CONTRAST GRADE – A number or descriptive term assigned to a particular printing emulsion which identifies its contrast characteristic. In the range from zero through five, a normal contrast paper is usually considered to be two, with the lower numbers indicating a tendency toward lower contrast. Printing filters for use with variable contrast papers are numbered similarly. In some cases low contrast is indicated by the term "soft" while high contrast paper are labeled "hard".
CONTRASTY – higher than-normal contrast. The range of density in a negative or print is higher than it was in the original scene.
CONVERTER – An optical unit which can be interposed between the camera body and lens to effectively double or triple the lens focal length; usually, but not always, with some loss of image quality, and always with a substantial loss of lens speed. Sometimes called an Extender.
COPY – To reproduce via photography. An original which is subjected to photographic reproduction.
COVERAGE – The area of the image (formed by a lens) which is of useful quality. Also, the area of the subject which the lens can record as an image of useful quality.
CROPPING – Printing only part of the image that is in the negative or slide.
CROSS LIGHT – Light striking the subject from one side.
CURTAIN SHUTTER – A shutter variety in which slit or opening in a strip of metal or cloth is made to travel past the film surface to effect the exposure.
CURVATURE OF FIELD – The tendency of a simple lens to form its image on a spherical, rather than flat, plane.
DARK SLIDE – The black plastic or fiber sheet which is inserted into a FILM HOLDER through a light tight slot to seal the film chamber against light.
DAYLIGHT – Sunlight or skylight or any mixture of the two. For the purposes of color photography, daylight is considered to have a color temperature of from about 5500 degree K. to 6000 degrees K. and this condition is likely to exist when the sun is high and slightly overcast. Under other conditions the color of daylight is likely to be quite different from the "norm" and must be filtered if "normal" color rendition is desired.
DENSE – Descriptive of a negative which is dark overall, or of an area of a negative which has a heavy sliver deposit and therefore transmits only a little light.
DENSITOMETER – An instrument designed to measure the amount of light transmitted by individual small areas of a negative, thus appraising the density of the areas.
DENSITY RANGE – The range of densities represented by, for example, a negative image. It is found by subtracting the lowest density value from the highest, and is expressed numerically.
DEPTH OF FIELD – The region of acceptable sharp focus around the subject position, extending toward the camera and away from it, from the plane of sharpest focus. The boundaries of the depth of field are referred to as the neat limit and the far limit. Depth of field depends on the lens opening, the focal length of the lens, and the distance from the lens to the subject.
DEPTH OF FIELD SCALE -- A calibrated scale, ring or chart, often a part of the camera lens mount, on which the depth of field for any distance and aperture setting is indicated.
DEPTH OF FOCUS -- The distance range over which the film could be shifted at the film plane inside the camera and still have the subject appear in sharp focus; often misused to mean depth of field.
DEVELOPER – Chemical solution used to covert a latent image to a visible image. Converts exposed silver halide into metallic silver. DEVELOPMENT – The process of chemically treating a photographic material to produce a visible image. Sometimes used to include the fixing and washing operations.
DEVELOPMENT FOG – Fog formed by the partial development of unexposed grains of emulsion; caused by developing the sensitized material under unsuitable conditions.
DIAPHRAGM – The assembly of thin metal leaves, usually incorporated into the lens barrel or shutter assembly, which can be adjusted to control the size of the lens aperture.
DICHROIC FILTER – A filter, usually of glass coated with a thin film of some durable material, which has the unique ability to transmit certain colors while reflecting the rest of the spectrum. Because the transmitted and reflected colors are complementary the filter appears to change color in certain lights, hence the "dichroic." Dichroic filters are highly resistant to heat and fading and are therefore especially suitable for use in color printing applications.
DIFFUSER – Any light-scattering medium placed in the path of a beam of light to soften its character, such as matt white reflectors behind or frosted or opal glass in front of the light source.
DIFFUSION – The scattering of light in all directions by reflection from a rough surface or passage through a translucent medium.
DIFFUSION-CONDENSER ENLARGER – An enlarger that combines diffuse light with a condenser system, producing more contrast and sharper detail than a diffusion enlarger but less contrast and blemish emphasis than a condenser enlarger.
DIFFUSION ENLARGER – An enlarger that scatters light before it strikes the negative, distributing light evenly on the negative. Detail is not as sharp as with a condenser enlarger; negative blemishes are minimized.
DIOPTER – An optician’s term which identifies the power of a lens. It expresses the reciprocal of the lens focal length in meters and is usually preceded by a plus or minus sign to indicate whether the lens is positive (converging) or negative (diverging). Thus, a close-up (positive) lens having a focal length of 50 cm (1/2 meter) would be labeled a +2 lens. DISTORTION – – Sometimes referred to as linear distortion or curvilinear distortion, it is an aberration of the lens which is characterized by variable magnification of the image. The effect increases toward the edges of the image area and will cause straight lines near the edges of the subject field to be formed near the image margins as curved lines. Two forms are identified, Pincushion and Barrel distortion.
DODGE – – To shade a portion of a print during exposure.
DODING – – Holding back the image forming light from a part of the image projected on an enlarger easel during the part of the basic exposure time to make that area of the print lighter.
DOUBLE EXPOSURE – – Two pictures taken on one frame of film, or two images printed on one piece of photographic paper.
DRY-MOUNTING – – A method of mounting prints on cardboard or similar sheet materials. Dry-mounting tissue placed between the print and mount board is softened by the heat of a dry-mounting press to effect the bond.
DRY-MOUNTING PRESS – – A machine for dry-mounting prints. It has a large flat metal pressure plate which can apply uniform pressure and thermostatically controlled heat on the prints to be mounted.
DRY-MOUNTING TISSUE – – A thin tissue paper impregnated with shellac or some similar material, which, when heated sufficiently, softens to become an effective adhesive for paper.
DX CODE – – A system of encoding ISO speeds onto 35mm film cassettes. A DX coded camera can read the code and set the film speed automatically.
EASEL – – A device to hold photographic paper flat during exposure, usually equipped with an adjustable metal mask for framing.
EMULSION – – A thin coating of light-sensitive material, usually silver halide in gelatin, in which the image is formed on film and photographic papers.
EMULSION SIDE – – The side of the film coated with emulsion. In contact-printing and enlarging, the emulsion side of the film - dull side - should fact the emulsion side of the photo paper - shiny side. ENLARGEMENT – – A print that is larger than the negative or slide: blowup.
ENLARGER – – A device consisting of light source, a negative holder, and a lens, and means of adjusting these to project an enlarged image from a negative onto a sheet of photographic paper.
EXHAUSTION – – Inactive state of a solution caused by depletion of its chemical components.
EXISTING LIGHT – – Available light. Strictly speaking, existing light covers all natural lighting from moonlight to sunshine. For photographic purposes, existing light is the light that is already on the scene or project and includes room lamps, fluorescent lamps, spotlights, neon signs, candles, daylight through windows, outdoor scenes at twilight or in moonlight, and scenes artificially illuminated after dark.
EXPOSE – – To subject a material to the action of light.
EXPOSURE – – The quantity of light allowed to act on a photographic material; a product of the intensity (controlled by the lens opening) and the duration (controlled by the shutter speed or enlarging time) of light striking the film or paper.
EXPOSURE DETERMINATION – – Measuring or estimating the brightness of parts or the whole of a subject by exposure meters.
EXPOSURE FACTOR – – Figure by which the exposure indicated for an average subject and/or processing should be multiplied to allow for non-average conditions. Usually applied to filters, sometimes to lighting or processing.
EXPOSURE INDEX – – Number assigned to a photographic material.
Based on emulsion speed and latitude, exposure meter characteristics and technique, and proposed conditions of processing. Used to determine the appropriate exposure under different lighting conditions when using correspondingly calibrated exposure meters. It is identical with the working speed of the material as specified by international standards.
EXPOSURE LATITUDE – – The range of camera exposures, from underexposure to overexposure, that will produce acceptable pictures from a specific film.
EXPOSURE METER – – An instrument with a light - sensitive cell that measures the light reflected from or falling on a subject; used as an aid to selecting the exposure setting. The same as a light meter.
EXPOSURE SETTING – – The lens opening plus shutter speed selected to expose the film.
EXTENSION TUBE – – Hollow tube with male and female lens mount fittings on either end. Used to extend the lens from the film plane in close-up photography.
FACTOR – – A number by which the duration or effect of some action or process must, for some reason, be multiplied.
FAST – – A term used to describe lenses of large relative aperture or films of high sensitive. Sometimes also applied to unusually sensitive papers.
FILM – – A photographic emulsion coated on a flexible, transparent, plastic base.
FILM HOLDER – – Thin container of plastic, metal, or wood, usually black, designed to hold two sheets of film in separate compartments, back to back.
FILM SPEED – – The sensitivity of a given film to light, indicated by a number such as ISO 200; the higher the number, the more sensitive or faster the film.
FILTER FACTOR – – The number by which an exposure given through a filter must be multiplied to compensate for the absorption of light by the filter.
FIX – – To make the film insensitive to further exposure to light, usually by bathing the emulsion with a solution containing Hypo or some other effective silver halide solvent. Such a solution is called a fixing bath.
FIXING BATH – – A solution that removes any light sensitive silver halide crystals not acted upon by light or developer, leaving a black - and - white negative or print unalterable by further action of light.
FLASH – – A brief, intense burst of light from a flashbulb or an electronic flash unit, usually used where the lighting on the scene is inadequate for picture taking.
FLAT – – Too low in contrast. The range in density in a negative or print is too short.
FOCAL LENGTH – – The distance from the optical center of the lens to
Its focused image, when the lens is focused at infinity.
FOCAL PLANE – – Plane through the principal focus of a lens and perpendicular to its optical axis. To record a sharp image the emulsion surface of the film in a camera must be positioned in the focal plane of the taking lens. That plane in the camera where the sharply focused image is formed.
FOCUS – – To adjust the lens/image plane separation to obtain a sharp image of an object at a specified distance in front of the camera.
FOGGING – – Darkening or discoloring of a negative or print or lighting or discoloring of a slide caused by: (1) exposure to non-image forming light to which the photographic material is sensitive, (2) too much handling in air during development, (3) over-development, (4) outdated film or paper, or (5) storage of film or paper in a hot, humid place. f/STOP – – The numerical expression of the aperture diameter of a lens as a fraction of the focal length. Number indicating the light-passing power of a lens.
GRAIN – – The visible granular texture of the silver image, caused by apparent clumping of the individual silver particles, viewed under magnification.
GRAININESS – – The sand like or granular appearance of a negative, print, or slide resulting from the clumping of silver grains during development of the film. Graininess becomes more pronounced with faster film, increased density in the negative, and degree of enlargement.
GRAY CARD – – A card of known reflectance, usually 18 percent, intended to be placed in the subject area and used as a meter target in the determination of exposure. Also used in color photography to establish a neutral reference for the adjustment of print color.
GRAY SCALE – – The gradation of an image. A strip of film or paper displaying individually uniform areas of density ranging from light to dark in a series of steps. Also sometimes called step tables, they are used in testing the sensitivity and contrast characteristics of photographic materials.
GUIDE NUMBER – Figure allocated to a light source, usually flash, representing the product of lens aperture and light-to-subject distance required for correct exposure under average conditions using a specified photographic material.
HYPO – The common name for sodium thiosulfate, also used by photographers when speaking of the complete fixing bath.
ILLUMINATION – The distribution of light from one or more sources over the subject being photographed and over the surface of the sensitive material.
IMAGE – The photographic representation of the subject photographed. The visible result of exposing and developing a photographic emulsion.
INCIDENT LIGHT – The light reaching the subject from any and all sources.
INCIDENT LIGHT METER – Exposure meter designed to integrate the light reaching it over a very wide acceptance angle and used to measure the light intensity falling on a scene rather than that reflected from it. The usual form is a photoelectric meter with a diffusing screen or cone over the face of the cell. It is pointed toward the camera from the subject position.
INFINITY – In photography, lens setting position on the focusing scale of a camera (indicated by the symbol of a lazy eight) which results in a sharp image of distant objects.
INVERSE SQUARE LAW – A statement to the effect that
"Illumination intensity on a surface will vary inversely with the square of the distance from the light source to the illuminated surface".
ISO – International Standards Organization. An organization whose major purpose is to gather, correlate, and standardize information about photographic material, processes, and equipment. In 1974 the ISO adopted a standard for determining film speeds that, in effect, combined out existing ASA system with the German DIN system. ISO film speeds, as presently used in this country, include both, so that, for example, Plus-X film is now rated ISO 125.22` – the degree sign indicating the DIN logarithmic value.
ISO EXPOSURE INDEX – A numerical value assigned to film by the
International Standards Organization to indicate its speed and for use in computing correct exposure.
LATENT IMAGE – The invisible impression on the sensitized emulsion produced by exposure to light in the development-out processes. Development converts the latent image to a visible one.
LEAF SHUTTER – A type of shutter, usually operating in the space between the major lens components or immediately behind the lens, which consists of a number of then metal leaves or blades, arranged concentrically around the lens axis, pivoted so that they can either form an opening for the passage of light or overlap to block it.
LENS SPEED – Maximum light-transmitting power of a lens. The term is often used when referring to the maximum working aperture of a lens (its smallest f number)
LIGHTING TENT – Enclosure of translucent material inside of which subjects such as glass, silverware and jewelry are sometimes photographed, the camera lens projecting through a hole in one wall. Light entering the tent is so diffused that it is substantially shadowless and there is no reflected image of the camera from polished surfaces.
LIGHT METER – An instrument which measures light intensity. If supplied with a suitable computing scale, it becomes an exposure meter. The term is commonly used interchangeable with exposure meter. See exposure.
LIGHT TIGHT – Describes a container, room or space which light cannot enter or leave, or a door or baffle or aperture which light cannot penetrate.
LINE NEGATIVE – Negative consisting of two tones only, clear transparent lines or letter against a maximum density background, with no intermediate densities.
MACRO LENS – Camera lenses (typically interchangeable lenses on 35mm cameras) fitted with an extended focusing mount to permit focusing from infinity to same size reproductions. Camera lens specially corrected for optimum definition at same size reproduction.
MAGNIGICATION – Relationship between the size of the object photographed and the image of it formed by the lens.
MAXIMUM APERTURE – The largest useful opening of the lens.
Wide open.
NEGATIVE – A photographic image in which the tones of the subject have been recorded in reverse.
NEGATIVE CARRIER – The frame of glass or metal which holds the negative in printing position in the enlarger.
NITROGEN BURST – Method of agitating processing solutions by introducing nitrogen gas into the bottom of the processing rank through a distributor nozzle. The bubbles of gas rising through the liquid form an effective and harmless stirring device.
NORMAL LENS – Any lens whose focal length is approximately equal to the diagonal measurement of the film frame.
OBLIQUE LIGHTING – Light striking the subject from the side relative to the position of the camera; produces shadows and highlights to create modeling on the subject.
OPAL GLASS – A translucent glass having a milky or "opal-scent" appearance, used to diffuse light.
OPAQUE – Incapable of transmitting light. A special fine-ground tempera paint, usually brick-red or black, for use in blocking out unwanted areas of the negative image prior to printing.
OPEN FLASH – Method of taking pictures with flash in which the shutter is opened on time or blub and the flash is fired manually.
ORTHO – Abbreviation of orthochromatic.
ORTHOCHROMATIC – Photographic materials sensitive to all colors except the orange and red regions of the spectrum. Type of emulsion which is sensitive to visible blue and green, but not to red.
OVERDEVELOPMENT – Excessively long development of photographic material which results in very dense and contrasty negatives or fogged and stained prints.
OVEREXPOSURE – Excessive amount of light falling on the sensitized material during exposure resulting in dense negative with opaque highlights or prints with blocked up shadows and veiled highlights.
PAN – It describes a type of emulsion, "panchromatic" which is sensitive to all colors of the visible spectrum
PANCHROMATIC – Describes an emulsion sensitive to blue, green and some, or all, of the red region of the spectrum.
PAPER NEGATIVE – A negative image on a paper base, prepared either by exposing the paper directly in a camera or by printing from a positive transparency.
PERSPECTIVE – The apparent relation between the shape, visual scale and position of visible objects.
PERSPECTIVE DISTORTION – Change in the shape and foreshortening of the three-dimensional objects in a picture, resulting from the use of a wide-angle lens.
PHOTOMACROGRAPHY – Small objects photographed at greater than life size by the use of long bellows and short focal length lens on the camera.
PRIMARY COLORS – Three colors of light, Blue, Green, and Red, which when mixed in equal amounts, produce white light.
PRINT – In photography, the term is generally used to identify and image on paper, produced by photographic means. It is usually understood to mean a positive image, and implies a final image rather than an intermediate one in some longer process.
PRINTING FRAME – A shallow, rectangular frame of wood or metal equipped with a removable front glass and a separate folding back which can be fastened to the frame with leaf springs so as to hold a negative and a sheet of printing paper against the glass smoothly and tightly. In use, light is allowed to shine through the front glass and through the intervening negative to reach the printing emulsion. Also called a contract printing frame.
PRINTING PAPER – Paper coated with a light-sensitive substance, to be used for making photographic images.
POSITIVE – An image in which the tones or colors are similar to those of the subject.
PROCESS – To subject photographic films or papers to chemical treatment, such as, for example, development. The sequence of chemical steps required to produce the desired image or result.
PUSH PROCESSING – Increasing the development time of a film to increase its effective speed (raising the ISO number for initial exposure) for low-light situations; forced development.
RECIPROCITY FAILURE – When the product of light intensity and time of exposure remains constant there is a relative loss of sensitivity of photographic emulsion at very low or high intensities for correspondingly longer or shorter exposures.
REFLECTANE – Describes the ability of a surface to reflect light.
REFLECTED LIGHT METER – Exposure meter used to measure the light reflected from a scene as distinct from incident light meters which measure light falling on the subject. Most meters built into cameras are reflected light meters and indicated exposures on the assumption that the proportion of light to dark areas in most scenes is roughly constant.
REFLECTION – Re-direction of light or other radiation by a surface.
Reflection may be specular if the surface is polished, each light ray being thrown back in the direction from which it came. If the surface is matted, reflection becomes more or less diffuse, the light being scattered in all forward directions.
REFLECTOR – A surface used to reflect light. Photographic reflectors are usually sheets of cardboard, plywood, masonite, or stretched fabric, painted white or covered with metal foil. RELATIVE APERTURE – The relationship between the diameter of the lens opening and the focal length of the lens. It is found by dividing the focal length by the diameter and is, strictly speaking, the number so found-as distinguished from the Aperture which included the prefix f .
RESIN COATED PAPER – RC Paper. Printing papers employing a special base material treated during manufacture with a "Resin Coating" which, by limiting water absorption, allows for very rapid processing and reduces drying time.
RETICULATION – Cracking or distorting of the emulsion during processing, usually caused by wide temperature or chemical activity difference between the solutions.
REVERSAL – (1) Process of exposing or processing a normally negative working photographic material to obtain a positive instead of a negative image. (2) Effect in which a negative image is converted locally or entirely into a positive or vice verso under particular conditions of exposure or processing.
REVERSED NEGATIVE – Negative in which the image is reversed left to right by either photographing the original through a right angled (reversing) prism or mirror or by stripping and laterally reversing the emulsion. The final print is a lateral inversion of the negative.
REVOLVING BACK – Technical or studio large format camera feature which permits the film holder to be rotated in its plane so that the long dimension of the negative material is either vertical or horizontal.
RISING FRONT – Camera lens panel or frame constructed so that it can be moved vertically to allow the lens to be raised above -or dropped below- the normal position. Used when photographing objects such as tall buildings from a near viewpoint with the camera pointing at an upward angle, while keeping the camera back vertical to ensure parallel rendering of vertical lines.
ROLL FILM – Film supplied in rolls rather than sheets, but especially those films protected from light by paper leaders rather than those supplied in protective cartridges of metal or plastic.
SAFELIGHT – Illumination, used in various darkroom processed, which is of color and intensity which will not appreciable affect the emulsions being handled. Blue sensitive emulsions can be handled in a yellow safelight and orthochromatic emulsions are generally unaffected by orange or red safelight. Image density resulting from excessive exposure to safelight or to an inappropriate safelight color, is known as safelight fog.
SCALE – In image formation, the liner ratio of image size to object size. If this ratio is greater than one the result is magnification. In a photographic enlargement the image is the projected image and the negative is the object. When subject and image are the same size the scale is 1/1 usually indicated by s/s (same size). Because the scale is linear it must be in squares to give the area. A linear magnification of 4x is equal to an area magnification of 16x.
SENSITIVITY – In photography, the susceptibility of an emulsion to alteration by light energy.
SEPARATION – The visual quality of any image area which makes it visible against its background.
SHADOW AREA – Any region of a photographic image which corresponds to an area of shade or shadow in the original subject.
SHARP – Term used to denote the distinctness of detail in photograph or the focused image on the ground glass of a camera.
SHEET FILM – Film supplied in individual pieces; also called cut film.
SHEET FILM HOLDER – See Film Holder.
SHELF LIFE – Period of time before deterioration results in an appreciable loss of speed or growth of fog in an unexposed, properly wrapped and stored sensitized material. Refrigerated storage increases the useful working life of most types of photo-sensitive material.
SHIFTS AND SWINGS – The various adjustments of the front and rear standards of a view camera, provided for the purpose of facilitating framing, control of perspective, and the efficient use of the available depth of field.
SHUTTER – A device installed in front, behind, or between the elements of a lens, or at the focal plane of the camera, to control the duration of exposure.
SHUTTER PRIORITY – A camera feature that lets you select the desired shutter speed, and the camera sets the aperture for proper exposure. When you change the shutter speed or when the light level changes, the aperture changes accordingly.
SHUTTER RELEASE – The lever or plunger which, when pressed allows the shutter mainspring to operate the shutter mechanism and make the exposure.
SHUTTER SPEED – (1) The duration of the interval of exposure. (2)
The marked settings on a shutter dial. The numbers represent the denominators of fractions of which 1 is the numerator.
SLOW – A term used to describe the linger exposure intervals provided by the shutter, as "one-half second is a slow speed." Also applied to relatively insensitive emulsions, as a slow film.
SOFT – Describes an image which is not sharp; that is, one which is blurred, diffused, or not accurately focused. Photographic emulsions, specifically printing papers, which tend to produce images of lower-than-normal contrast; for example, the paper grades 0 and 1, and some others of similar characteristics, are called soft papers.
SPLIT-IMAGE RANGEFINDER – A variety of rangefinder in which the opposite halves of the image are displaced along a dividing line when the instrument is not properly focused. Correct distance is indicated when the image halves are adjusted to match.
SPOT METER – An exposure meter which measures reflected light or luminance, over a field of only a degree or two.
STOP – The aperture or f/number of lens. A change in exposure, from any cause, which doubles or halves the preceding one.
STOP BATH – A weak acid solution used immediately after development and before fixing, to stop the action of developer and prolong the life of the fixer.
STOP DOWN – To reduce the size of the aperture of a lens.
SWING BACK – On a screen focusing camera a hinged back which can be turned at an angle to the vertical to improve the perspective of the image and extend the depth of field covered. SWING FRONT – Lens panel of a camera hinged about its axis so that it can be used, in conjunction with the swing back, to control perspective and/or relocate the plane of maximum sharpness producing a similar result to an increase the depth of field
TACKING IRON – A small electrically heated, thermostatically controlled tool used to tack or attach dry-mounting tissue to the back of a print or to the mount board, so as to hold it in place while the print is being trimmed and heated in the dry-mount press.
TANK – A small, light tight container, in which film is placed for processing.
TELEPHOTO LENS – A lens that makes a subject appear larger on film than does a normal lens at the same camera-to-subject distance. A telephoto lens has a longer focal length and narrower field of view than a normal lens.
TENT LIGHTING – Lighting technique that involves isolating the subject in a plain environment or "tent", so that surface reflections and lighting effects can be closely controlled.
THIN – describes the appearance of a transparency image
(usually the negative) of low overall density.
THIN NEGATIVE – A negative that is under exposed or underdeveloped (or both). A thin negative appears less dense than a normal negative.
TIME – One of the marked speeds on some shutters. A shutter set on (T) time will open when the shutter release is pressed and will remain open until the release is pressed again. It is a convenient setting for exposure intervals of more than a few seconds.
TIME EXPOSURE – A comparatively long exposure made in seconds or minutes.
TRANSLUCENT – Describes a diffusing material which will transmit light, but not focused light. A very thin translucent surface is used on screens for back projection and back lighting of objects.
TRANSPARENCY – A positive photographic image on film, viewed or projected by transmitted light (light shining through film).
TRIPOD – A three-legged stand, usually adjustable in height and provided with a tilting and swiveling head, on which a camera can be fastened for support and stability during use.
TUNGSTEN LIHGT – Generally, the light emitted by a heated
Tungsten filament such as is contained in conventional electric light bulbs. Sometimes used to refer specifically to the light of special photographic tungsten filament bulbs which are designed to burn at either 3200K or 3400K. Also often used loosely to apply to artificial light in general, as distinguished from daylight.
TTL – Through-the-lens; describes a type of exposure meter, incorporated in the structure of a camera, which reads the
Intensity of the image light transmitted by a lens.
TYPE L FILM – Color sheet or roll film balanced for 3200K lamps and exposure time of 1/10 to 60 seconds. L indicates that the film is designed to show minimum reciprocity failure at the relatively long exposure times.
TYPE S FILM – Color sheer or roll film balanced for daylight, electronic flash or blue flash bulbs and exposure times of 1/10 second or shorter, S standing for short exposure time.
UNDEREXPOSURE – A condition in which too little light reaches the film, producing a thin negative, S standing for short exposure Why is Photography an Art?
Photography that is done as a fine art -- that is, done to express the artist's perceptions and emotions and to share them with others
Photography is an art because it takes a special eye for composition, lighting, and background.
Think about drawing. If you are drawing, say, a face, you can change the expression your subject by a slight change in the way you draws the eye, the mouth, any part of the face. You can shade darkly, use a thick, soft pencil to create heavy lines, and use the positioning of the face to entirely change the mood to dark , deep, disturbed, or sad.
Photography is most definitely art! There is so many things you can do to photography. You can change the tints and colors. You can paint over photos, and develop them Importance of Crime Scene Photography
1. Permanent Record
A permanent record of the crime scene is considered indispensable to a successful presentation of the case in court. A crime scene that is altered through careless and haste can never be restored to its exact original condition.
2. Significance of certain aspects of the crime scene
Also, in the initial stages of an investigation, the significance of certain aspects of the crime scene may not be evident, although later they may vitally affect the issues in the case. The first step in the investigation of any crime is to photograph all aspects of the crime scene completely and accurately before any of the objects are removed or otherwise disturbed. Photographs should always be taken after the body or bodies have been removed. It is always better to take many photographs than to few.
3. Reconstruction of the crime scene
A study of photographs can also assist the trained investigator in reconstructing the crime scene and developing conclusions about how the crime occurred. In addition, the photographs will make the job of the prosecutor much easier when a case if presented in a court room.
Elements of Photography
1. Camera
2. Sensitized Materials (film and the Photo paper)
3. Light
4. Chemical Process Uses of Photographs:
a. Identification of the subject Basic requirements of photographs to be admitted as evidence in court: a) Accurate representations b) Free of Distortion c) Material and relevant d) Unbiased
What is a Camera?
Is a light tight box, with a means of forming the image( lens) with a means of holding a sensitize materials (film holder) and a with a means of controlling the amount of light that will reach the film( shutter)
The camera is a box that controls the amount of light that reaches a piece of light sensitive film or other surface inside.
Important controls in the camera
1) Focusing Control
a) Split Image
Out of Focus Sharp Focus
b) Microprism c) Ground Screen
2) Aperture
3) Shutter Speed SLR CAMERA
A single-lens reflex camera (SLR) typically uses a mirror and prism system (hence "reflex", from the mirror's reflection) that permits the photographer to view through the lens and see exactly what will be captured, contrary to viewfinder cameras where the image could be significantly different from what will be captured.
The photographer can see the motive before taking an image by the mirror. When taking an image the mirror will swing up and light will go to the sensor instead.
Camera lens
Reflex mirror
Focal-plane shutter
Image sensor
Matte focusing screen
Condenser lens
Pentaprism/pentamirror Viewfinder eyepiece
Camera Motion
Camera motion can be the cause of lack of sharpness .There is two prime causes of camera motion:
First cause is vibration and it is usually caused by body movement including the beating of the heart.
Second Cause of camera motion is actual camera movement caused by the improper handling of the camera.
What is Over and Under Exposure?
UNDEREXPOSURE – A condition in which too little light reaches the film, producing a thin negative, S standing for short exposure
OVEREXPOSURE – Excessive amount of light falling on the sensitized material during exposure resulting in dense negative with opaque highlights or prints with blocked up shadows and veiled highlights.
THE TEN LEGAL COMMANDMENTS OF PHOTOGRAPHY I. Anyone in a public place can take pictures of anything they want. Public places include parks, sidewalks, malls, etc. Malls? Yeah. Even though it’s technically private property, being open to the public makes it public space.
II. If you are on public property, you can take pictures of private property. If a building, for example, is visible from the sidewalk, it’s fair game.
III. If you are on private property and are asked not to take pictures, you are obligated to honor that request. This includes posted signs.
IV. Sensitive government buildings (military bases, nuclear facilities) can prohibit photography if it is deemed a threat to national security.
V. People can be photographed if they are in public (without their consent) unless they have secluded themselves and can expect a reasonable degree of privacy. Kids swimming in a fountain? Okay. Somebody entering their PIN at the ATM? Not okay.
VI. The following can almost always be photographed from public places, despite popular opinion: accident & fire scenes, criminal activities bridges & other infrastructure, transportation facilities (i.e. airports) industrial facilities, Superfund sites public utilities, residential & commercial buildings children, celebrities, law enforcement officers
UFOs, the Loch Ness Monster, Chuck Norris
VII. Although “security” is often given as the reason somebody doesn’t want you to take photos, it’s rarely valid. Taking a photo of a publicly visible subject does not constitute terrorism, nor does it infringe on a company’s trade secrets.
VIII. If you are challenged, you do not have to explain why you are taking pictures, nor to you have to disclose your identity (except in some cases when questioned by a law enforcement officer.)
IX. Private parties have very limited rights to detain you against your will, and can be subject to legal action if they harass you.
X. If someone tries to confiscate your camera and/or film, you don’t have to give it to them. If they take it by force or threaten you, they can be liable for things like theft and coercion. Even law enforcement officers need a court order.
WHAT TO DO IF YOU’RE CONFRONTED
Be respectful and polite. Use good judgment and don’t escalate the situation. If the person becomes combative or difficult, think about calling the police.
Threats, detention, and taking your camera are all grounds for legal or civil actions on your part. Be sure to get the person’s name, employer, and what legal grounds they claim for their actions.
If you don’t want to involve the authorities, go above the person’s head to their supervisor or their company’s public relations department.
Call your local TV and radio stations and see if they want to do a story about your civil liberties.
Put the story on the web yourself if need be.
Three (3) Pillars of Photography
1) What is Aperture? Simply put, aperture is a hole within a lens, through which light travels into the camera body. It is easier to understand the concept if you just think about our eyes. Every camera that we know of today is designed like human eyes. The cornea in our eyes is like the front element of a lens – it gathers all external light, then bends it and passes it to the iris. Depending on the amount of light, the iris can either expand or shrink, controlling the size of the pupil, which is a hole that lets the light pass further into the eye. The pupil is essentially what we refer to as aperture in photography. The amount of light that enters the retina (which works just like the camera sensor), is limited to the size of the pupil – the larger the pupil, the more light enters the retina. So, the easiest way to remember aperture, is by associating it with your pupil. Large pupil size equals large aperture, while small pupil size equals small aperture.
2) Size of Aperture – Large vs Small Aperture The iris of the lens that controls the size (diameter) of the aperture is called “diaphragm” in optics. The sole purpose of the diaphragm is to block or stop all light, with the exception of the light that goes through the aperture. In photography, aperture is expressed in f-numbers (for example f/5.6). These f-numbers that are known as “f-stops” are a way of describing the size of the aperture, or how open or closed the aperture is. A smaller f-stop means a larger aperture, while a larger f-stop means a smaller aperture. Most people find this awkward, since we are used to having larger numbers represent larger values, but not in this case. For example, f/1.4 is larger than f/2.0 and much larger than f/8.0. Take a look at this chart (image courtesy of Wikipedia): The size of the circle represents the size of the lens aperture – the larger the f-number, the smaller the aperture.
What is Depth of Field? One important thing to remember here, the size of the aperture has a direct impact on the depth of field, which is the area of the image that appears sharp. A large f-number such as f/32, (which means a smaller aperture) will bring all foreground and background objects in focus, while a small f-number such as f/1.4 will isolate the foreground from the background by making the foreground objects sharp and the backgroundblurry.
Image on left shot at f/2.8, Image on right shot at f/8.0
As you can see, just changing the aperture from f/2.8 to f/8.0 has a big effect on how much of WALL-E is in focus and how visible the background gets. If I had used a much smaller aperture such as f/32 in this shot, the background would be as visible as WALL-E. Another example: Mailboxes - Aperture set to f/2.8
In the above example, due to the shallow depth of field, only the word “Cougar” appears sharp, while everything else in the front and behind of that word is blurred. If I had used a larger aperture such as f/1.4 and focused on one of the letters, probably only that letter would have been sharp, while everything else would have been blurred out. The larger the aperture, the smaller the area in focus (depth of field).
HOME / PHOTOGRAPHY TUTORIALS / UNDERSTANDING SHUTTER SPEED – A BEGINNER’S GUIDE Understanding Shutter Speed – A Beginner’s Guide Man finds $1 million winning lottery ticket while cleaning (BWNToday) dec 20 2009 BY NASIM MANSUROV79 COMMENTS Shutter Speed is one of the three pillars of photography, the other two being ISO and Aperture. Shutter speed is where the other side of the magic happens – it is responsible for creating dramatic effects by either freezing action or blurring motion. In this article, I will try to explain everything I know about shutter speed in very simple language.
Dolphin - 1/1600 Shutter Speed
1) What is a Camera Shutter? Before reading this article, I highly recommend reading about what a DSLR is and what it consists of. Simply put, a camera shutter is a curtain in front of the camera sensor that stays closed until the camera fires. When the camera fires, the shutter opens and fully exposes the camera sensor to the light that passes through the lens aperture. After the sensor is done collecting the light, the shutter closes immediately, stopping the light from hitting the sensor. The button that fires the camera is also called “shutter” or “shutter button”, because it triggers the shutter to open and close. 2) What is Shutter Speed? Shutter speed, also known as “exposure time”, stands for the length of time a camera shutter is open to expose light into the camera sensor. If the shutter speed is fast, it can help to freeze action completely, as seen in the above photo of the dolphin. If the shutter speed is slow, it can create an effect called “motion blur”, where moving objects appear blurred along the direction of the motion. This effect is used quite a bit in advertisements of cars and motorbikes, where a sense of speed and motion is communicated to the viewer by intentionally blurring the moving wheels. How shutter speed is measured Shutter speeds are typically measured in fractions of a second, when they are under a second. For example 1/4 means a quarter of a second, while 1/250 means one two-hundred-and-fiftieth of a second or four milliseconds. Most modern DSLRs can handle shutter speeds of up to 1/4000th of a second, while some can handle much higher speeds of 1/8000th of a second and faster. The longest shutter speed on most DSLRs is typically 30 seconds (without using external remote triggers). 4) Fast, slow and long shutter speeds Fast shutter speed is typically whatever it takes to freeze action. For me, it is typically above 1/500th of a second for general photography and above 1/1000th of a second for bird photography.
Caspian Tern - 1/2000th of a second
Slow shutter speed is considered to be the slowest shutter speed that you can handle without introducing camera shake. Some of the newer Nikon lenses such as the Nikon 70-200mm VR II have special “vibration reduction” technologies within the lens that can handle shutter speeds of up to 1/10th of a second (depending on photographer’s technique), hand-held! How about long shutter speed? Long shutter speeds are typically above 1 second, when you have to use a tripod to get acceptably sharp images (for low-light/night photography or to capture movement). 5) How to set shutter speed Most cameras handle shutter speeds automatically through in-camera metering. When the camera is set to “Auto” mode, both shutter speed and aperture are automatically selected by the camera. When you shoot in “Aperture Priority” mode, you set the lens aperture, while the camera automatically sets the shutter speed. There are two ways to manually set the shutter speed: a) By setting the camera to “Shutter Priority” mode, where you set the shutter speed and the camera automatically selects the aperture. b) By setting the camera to “Manual” mode, where you set both shutter speed and aperture manually. I recommend letting the camera select the correct shutter speed for you. I personally shoot in “Aperture Priority” mode 99% of the time and I let my camera calculate the shutter speed for me. 6) How to find shutter speed Do you know how to find out what your camera shutter speed is set to? It is typically very easy to find the shutter speed. On Nikon DSLRs that have a top panel, the shutter speed is typically located on the top left corner:
Nikon D90 Top Panel - Shutter Speed
If you look through the viewfinder, it should also be the number on the bottom left side of the screen. On most DSLRs, you will not see the shutter speed as a fraction of a second – it will typically be a regular number. When the shutter speed is slower than or equals to one second, you will see something like 1″ or 5″ (the ” sign indicates a full second). If you still can’t find the shutter speed, set your camera to “Aperture Priority” mode, then look into the viewfinder and point at a really dark area. Remember the numbers in the display, then switch to a very bright area and see what number changes. The number that changes is your shutter speed.
Read more: http://photographylife.com/what-is-shutter-speed-in-photography#ixzz3AiQgSYMC 1) What is ISO? In very basic terms, ISO is the level of sensitivity of your camera to available light. The lower the ISO number, the less sensitive it is to the light, while a higher ISO number increases the sensitivity of your camera. The component within your camera that can change sensitivity is called “image sensor” or simply “sensor”. It is the most important (and most expensive) part of a camera and it is responsible for gathering light and transforming it into an image. With increased sensitivity, your camera sensor can capture images in low-light environments without having to use a flash. But higher sensitivity comes at an expense – it adds grain or “noise” to the pictures. Take a look at the following picture (click to open a larger version):
ISO 200 and ISO 3200 Comparison
The difference is clear – the image on the right hand side at ISO 3200 has a lot more noise in it, than the one on the left at ISO 200. Every camera has something called “Base ISO“, which is typically the lowest ISO number of the sensor that can produce the highest image quality, without adding noise to the picture. On most of the new Nikon cameras such as Nikon D5100, the base ISO is typically 200, while most Canon digital cameras have the base ISO of 100. So, optimally, you should always try to stick to the base ISO to get the highest image quality. However, it is not always possible to do so, especially when working in low-light conditions. Typically, ISO numbers start from 100-200 (Base ISO) and increment in value in geometric progression (power of two). So, the ISO sequence is: 100, 200, 400, 800, 1600, 3200, 6400 and etc. The important thing to understand, is that each step between the numbers effectively doubles the sensitivity of the sensor. So, ISO 200 is twice more sensitive than ISO 100, while ISO 400 is twice more sensitive than ISO 200. This makes ISO 400 four times more sensitive to light than ISO 100, and ISO 1600 sixteen times more sensitive to light than ISO 100, so on and so forth. What does it mean when a sensor is sixteen times more sensitive to light? It means that it needs sixteen times less time to capture an image! ISO Speed Example: ISO 100 – 1 second ISO 200 – 1/2 of a second ISO 400 – 1/4 of a second ISO 800 – 1/8 of a second ISO 1600 – 1/16 of a second ISO 3200 – 1/32 of a second In the above ISO Speed Example, if your camera sensor needed exactly 1 second to capture a scene at ISO 100, simply by switching to ISO 800, you can capture the same scene at 1/8th of a second or at 125 milliseconds! That can mean a world of difference in photography, since it can help to freeze motion. When to increase ISO You should increase the ISO when there is not enough light for the camera to be able to quickly capture an image. Anytime I shoot indoors without a flash, I set my ISO to a higher number to be able to freeze motion. Other cases where you might want to increase ISO are when you need to get ultra-fast shots, like the bird picture I posted above. But before increasing the ISO, you should think if it is OK for you to introduce noise to the image. On many of the newer DSLRs, there is a setting for “Auto ISO”, which works great in low-light environments. The beauty of this setting, is that you can set the maximum ISO to a certain number, so when the ISO is automatically increased based on the amount of light, it does not cross the set barrier. So, if I want to limit the amount of grain in my pictures, I typically set the maximum ISO to 800. If you have any questions, comments or feedback, please post them in the comments section below. Please note that the above explanation of ISO is given in very basic/simple terms, similar to film sensitivity. Correctly defining ISO in digital cameras can get fairly complex. If you want to find out more about ISO in digital cameras, including the ISO 12232:2006 standard, please see this article from Wikipedia.
EXPOSURE Combinations
THE TWO (2) ADJUSTMENTS ON A CAMERA THAT CONTROLS THE AMOUNT OF LIGHT THAT REACHES THE FILM.
Depth of Field
Is the distance measured from the nearest to the farthest object in apparent sharp focus when the lens is set or focus at a particular distance. The term Depth of Field is used to describe how much of what the camera sees in focus.
Also known as the ZONE OF FOCUS
Smaller Opening-Shallow depth of field
Higher Opening- Narrower
I. TECHNICAL PHOTOGRAPHY
A. Basic equipment for crime scene photography
1. Camera(s)
2. Normal lens
3. Wide angle lens
4. Close-up lenses or accessories
5. Filters
6. Electronic flash(s)
7. Remote or sync cord for electronic flash(s)
8. Extra camera and flash batteries
9. Locking cable release
10. Tripod
11. Film
12. Owner's manuals for camera and flash
13. Notebook and pen
14. Ruler
15. Gray card
16. Index cards and felt pen
17. Flashlight
B. Lenses
1. Normal lens 2. Wide angle lens
3. Other lenses
C. Care and maintenance of crime scene photography equipment
1. Cleaning lens and camera
2. Camera repair
3. Protection from extreme heat and cold
4. Protection from rain
D.Film
1. Color vs. black and white
2. Print film vs. slide film
3. Film speed
4. Matching film to the light source
II. CRIME SCENE PHOTOGRAPHY IS TECHNICAL PHOTOGRAPHY.
A. Photographs must be correctly exposed, have maximum depth
of field, be free from distortion and be in sharp focus
1. Correctly exposed
a. Exposure is controlled by the shutter speed and
lens aperture
b. Automated camera exposure systems and automatic
flash units can be fooled and give incorrect
exposures
c. Front, side and back lighting
d. Light meters
e. Flair
f. Using gray card
g. Bracketing exposures 2. Maximum depth of field
a. Depth of field is the area in a photograph in
which objects are in sharp focus
b. How to control depth of field
c. Zone focusing
(1) Preview depth of field
3. Free from distortion (must have good perspective)
a. Use a normal focal length lens when ever
possible
b. Keep the camera as level as possible
c. Photograph with the camera at eye level when
ever possible
4. Sharp focus
a. Keep the camera steady
b. Focus carefully and use maximum depth of field
c. Look at the frame of your scene
III. FLASH AND NIGHT PHOTOGRAPHY
A. Types of flash illumination
1. Manual flash
a. Set f/stop for the flash-to-subject distance
2. Automatic flash
a. Uses distance ranges
b. A change to a new range requires a change in
f/stop
c. Never work an automatic flash at its maximum
range, especially in less than ideal conditions d. When in automatic flash, make sure the shutter
speed dial is set to the flash synchronization
speed
e. When photographing a high key scene (light or
reflective background) bracket <197> opening up
one or two f/stops
3. Dedicated flash
a. Sets correct flash synchronization speed when
the flash is in operation. Still uses
automatic sensor and ranges. The photographer
must set the appropriate f/stop for the
distance range
OR
b. Sets the correct flash synchronization speed
and f/stop for the automatic range selected
4. Dedicated TTL (Through-the-lens)
a. Uses a sensor inside the camera
b. Use smaller f/stops for short distances and
larger f/stops for long distances
c. For compensation or bracketing use the exposure
compensation dial
B. Problems with electronic flash
1. Flash synchronization
2. Coverage
a. Distances -- inverse square law of light
b. Long distances when outdoors at night or at
arson scenes 3. Reflective surfaces
a. Automatic flash units can shut off too soon due
to reflected light
4. Rain
C. Lighting techniques
1. Electronic flash (NOTE:Disregard the light meter in
the camera when using electronic flash)
a. Flash mounted on camera
b. Flash off camera
c. Bounce flash
(1) Bounce off a white or light colored
surface
(2) Manual flash: add the distance up and down
for the flash-to-subject distance then
figure in the absorbance loss (one to
three f/stops)
(3) Automatic flash with sensor facing the
subject: use a range for two times or more
times the actual flash-to-subject distance
d. Multiple flash
(1) Distance the flash units to provide the
same f/stop for each flash
2. Available light (no electronic flash)
3. Painting with light
a. The shutter is left open while the light source
is moved around until all of the scene is
properly illuminated b. Procedure
(1) Mount the camera on a sturdy tripod
(2) Equip the camera with a lens shade (if
available)
(3) Screw a locking cable release into the
camera shutter release
(4) Set the shutter speed dial to B (bulb)
(5) Determine the f/stop based on the flash to
subject distance (not the camera to
subject distance)
(6) Focus carefully
(7) Depress the cable release and lock it to
hold the shutter open
(8) Fire the electronic flash to light areas
of the scene. The number of flashes and
angle of the flashes will depend on the
size and character of the scene. Do not
point the flash directly at the camera and
keep yourself out of the view of the
camera
(9) Unlock the cable release and allow the
shutter to close
(10) Advance the film
IV. CRIME SCENE PHOTOGRAPHY
A. Purpose of Crime Scene Photography
1. To record the original scene and related areas 2. To record the initial appearance of physical
evidence
3. It will provide investigators and others with this
permanent visual record of the scene for later use
4. Photographs are also used in court trials and
hearings
B. Admissibility of photographic evidence
1. Three major points of qualification of a photograph
in court
a. Object pictured must be material or relevant to
the point in issue
b. The photograph must not appeal to the emotions
or tend to prejudice the court or jury
c. The photograph must be free from distortion and
not misrepresent the scene or the object it
purports to reproduce
2. You do not need to be an expert in photography to
take crime scene photographs or testify about them
V. GENERAL CRIME SCENE PHOTOGRAPHY
A. Photographs are one way to record a crime scene
1. Field notes
2. Photographs
3. Sketches
B. Photographs
1. What photographs can show
2. What photographs do not show C. Five steps in recording the crime scene
1. Secure the scene
2. Take preliminary notes
3. Take overview photographs
4. Make a basic sketch
5. Record each item of evidence
D. Taking overview photographs
1. Purpose
a. To show the scene exactly as it was when you
first saw it
(1) If something was moved before you arrived,
don't try to reconstruct the scene as it
was. The photographs should show the
scene as you found it
2. Major crime photography
a. First discuss the crime, evidence and
photographs needed with other investigators at
the scene
b. Be careful not to destroy any evidence while
taking the photographs
c. Outside the scene
(1) Exterior of the building where the crime
occurred and in some cases the whole
locale
(2) Aerial photographs of the scene and the
surrounding area can be useful in some
types of cases (3) Original series of photographs should also
show all doors, windows and other means of
entrance or exit
d. Inside the scene
(1) Begin with a view of the entrance
(2) Then photograph the scene as it appears
when you first step into the room
(3) Next, move around the room to get
photographs of all the walls
(a) These photographs should also show
the positions of any potential items
of evidence
(4) Include photographs of other rooms
connected with the actual crime scene
3. Using video to record the crime scene
a. Frequently valuable to show an overview of the
scene
E. Photographs to record items of evidence
1. Take two photographs of each item of evidence
a. One should be an orientation (midrange) shot to
show how the item is related to its
surroundings
b. The second photograph should be a close-up to
bring out the details of the object itself
2. Measuring and marking devices
a. Take two photographs if a marking or measuring
device is used (1) One photograph without the device, the
other with the device
(2) So the defence can't claim that the scene
was altered or that the device was
concealing anything important
VI. PHOTOGRAPHING SPECIFIC CRIME SCENES
Note:Each crime scene has unique characteristics and the type
of photographs needed will be determined at the scene by the
investigator familiar with the crime.
A. Homicide
1. Use color film
2. Photographs (example: homicide inside a residence)
a. Exterior of the building
b. Evidence outside the building
c. Entrance into the scene
d. Room in which the body was found
e. Adjoining rooms, hallways, stairwells
f. Body from five angles
g. Close-up of body wounds
h. Weapons
j. Signs of activity prior to the homicide
k. Evidence of a struggle
l. View from positions witnesses had at time of
the crime
(1) Use a normal lens m. Autopsy
B. Suicide, other dead body calls
1. If there is any doubt, photograph the scene as a
homicide
C. Burglaries
1. Photographs (residential or commercial burglaries)
a. Exterior of building
b. Point of entry
c. Entrance into scene
d. Interior views
e. Area from which valuable articles were removed
f. Damage to locks, safe, doors, toolmarks
g. Articles or tools left at the scene by the
suspect
h. Trace evidence
i. Other physical evidence
D. Assaults, injuries
1. Photographing injuries
a. Face of victim in the photographs
b. Bruises
c. Bite marks
(1) Orientation shot
(2) Close-up at 90 degree angle to avoid
distortion
(3) Ruler in same plane as bite mark
(4) Focus carefully
(5) Bracket exposures 2. Equipment
a. Always use color film and no filter
b. Use color charts and rulers
c. Flash unit with diffused lighting
E. Traffic Accidents and Hit and Run Cases
1. Photographs at the accident scene
a. Where the vehicles came to rest and in what
position
(1) Photographs should show the relationship
of each vehicle with each other
b. Damage to vehicles
(1) Technical photographs of damage to a
vehicle
(a) Do not take any oblique or corner
photographs to show damage for
reconstruction purposes because they
are not aligned with the axis of
the vehicle. They tend to conceal
the amount and direction of the
damage.
(b) Take six photographs. Two from each
side in line with the axles. Take
one of each end of the vehicle,
straight on. If possible take one
more from overhead
(c) Use electronic flash to fill in
shadows within the damage c. Debris or marks on the roadway
d. View each driver had approaching the key point
of the accident.
e. View from the point a witness observed the
accident, at witness' eye level
f. Evidence to identify hit and run vehicles
2. Night photography
a. Use multiple flash, paint with light or
available light for extra long skidmarks or to
show two vehicles some distance apart
VII. USING FLASH FILL
A. Steps
1. Set the shutter speed to the camera's flash
synchronization speed (usually 1/60 second)
2. Use the camera's light meter to determine the
correct f/stop. Set that f/stop on your lens.
3. With the flash on manual, find the flash to subject
distance for the above f/stop.
4. Position the flash unit at that distance and take
the photograph.
VIII. PHOTOGRAPHING EVIDENCE
A. Fingerprints
1. When to photograph fingerprints
a. Before lifting on major cases or if the latent
may be destroyed when lifting b. To bring out detail in a latent
2. Equipment
a. 1:1 cameras and copy cameras
b. 35mm cameras with macro or close-up lens
attachments
c. Gray card for available light exposures
3. Films
a. Well defined fingerprints can be photographed
with color film but black and white film
provides more contrast and is preferred for
latent print photography
(1) Kodak T-MAX film. Develop in T-MAX
developer while increasing the development
time by 25% for increased contrast.
(2) Kodak TECHNICAL PAN 2415 film has a
variable contrast range between high and
low and a variable speed of ISO 25 to 320.
(a) For high contrast expose at ISO 100
and develop in HC-110
(3) Kodak KODALITH film for highest contrast
(a) Packaged as Kodak Ektagraphic HC
Slide Film (HCS 135-36) and has an
approximate ISO of 8.
(b) If developed in D-76 or HC-110 there
will be a limited gray scale.
(4) Ilford XP-2 black and white film can be
processed in color processors (a) ISO 400, fine grain with good
sharpness & resolution can be
processed in C-41 color chemistry
4. Filters
a. Color filters, when used in black and white
photography, can be used to build contrast by
either lightening or darkening the subject
(latent print) or by lightening or darkening
the background (background drop-out)
(1) To lighten a color, the color filter
closest to the color is used
(2) To darken a color, the opposite color
filter is used
(3) See Filter Chart for examples
5. Procedures
a. Establish the location of the latent
b. Close-up to show detail
(1) A 1:1 camera or device must be used, or
(2) A scale must be included in the photograph
on the same plane as the latent
(3) Photograph with the film plane parallel to
the latent surface
(4) Get as much depth of field as possible,
especially for curved surfaces
c. Exposure
(1) Available light exposures of latents with
normal contrast can be metered using a gray card
(2) Bracketing may reveal more detail in
"low contrast" latents.
(a) Underexposing the film will separate
the steps on the white end of the
gray scale. Overexposure will
separate the steps on the black end
of the gray scale.
(b) The latitude for black and white film
is generally two stops underexposure
and six stops overexposure. d. Specific types of fingerprint subjects
(1) Normal, dusted prints
(a) Usually can be photographed with no
problem
(2) Impressions in soft substances (wax,
putty, clay, adhesive tape, grease, etc.)
or in dust
(a) Use cross lighting at an oblique angle
(b) Preview with flashlight lighting
(3) Porous surfaces
(a) May need to use close to a 90 degree
lighting angle
(b) Preview with flashlight lighting
(4) Glass and mirrors
(a) Glass -- place white card or cloth
behind glass, use low oblique angle of light
(5) Perspiration prints on glass
(a) Use back (transmitted) lighting and
diffusion screen
(6) Ninhydrin fingerprint
(a) Use normal black and white film
(T-MAX or PLUS-X) with a green filter
and increase development time 25%
B. Impressions
1. Footprints and tire tracks
a. Procedure
(1) Take an orientation photograph to show
where in the scene the impression is
located
(2) Take a close-up for detail
(a) Use a scale on the same plane as the
impression
(b) Keep the film plane parallel to the
plane of the impression
(c) Block out ambient light and use a
strong light source at different
angles to find the light angle(s)
that shows the best detail in the
impression -- then put the electronic
flash or light source at that angle
for the photograph
(3) Photograph tire impressions in sections showing one circumference of the tire
(a) Use a tape measure for overlapping
photographs
C. Bloodstain photography
1. Use color film
2. Orientation photographs to show locations of
bloodstain evidence at the scene
3. Close-up photographs to show detail
a. Use a scale on the same plane as the bloodstain
b. Keep the film parallel to the plane of the
bloodstain
c. Use a low oblique light angle
D. Toolmarks
E. Serial numbers
F. Small items, copying, etc.
1. Close-up lenses and devices
2. Lighting
Photographs as Evidence
The principal requirements to admit a photograph (digital or film-based) into evidence are relevance and authentication. Unless the photograph is admitted by the stipulation of both parties, the party attempting to admit the photograph into evidence must be prepared to offer testimony that the photograph is an accurate representation of the scene. This usually means someone must testify that the photograph accurately portrays the scene as viewed by that witness.
Guidelines for Ensuring Your Digital Photographs Are Admissible
Develop a Standard Operating Procedure (SOP), Department Policy, or General Order on the use of digital imaging. The SOP should include when digital imaging is used, chain of custody, image security, image enhancement, and release and availability of digital images. The SOP should not apply just to digital, but should also include film-based and video applications as well.
Most importantly, preserve the original digital image. This can be done a variety of ways including saving the image file to a hard drive or recording the image file to a CD. Some agencies elect to use image security software.
Digital images should be preserved in their original file formats. The saving of a file in some file formats subject the image to lossy compression. If lossy compression is used critical image information may be lost and artifacts introduced as a result of the compression process.
If images are stored on a computer workstation or server, and several individuals would have access to the image files, make the files read-only for all but your evidence or photo lab staff. As an example, detectives could view any image files but they would not have rights to delete or overwrite those files.
If an image is to be analyzed or enhanced the new image files created should be saved as new file names. The original file must not be replaced (overwritten) with a new file.
The Mug Shot
Alphonse Bertillon didn't just establish the ground rules for crime scene photography -- he also invented the mug shot. Bertillon was influenced by eugenics, a then- common form of scientific racism. He believed that a person's character could be read through his or her genetic features and he used the standardized mug shot as an attempt to validate this theory.
Photograph the subject in front of the height scale without footwear to determine his/her exact height. Let the subject hold the case very\fier. Mug Shots shall be done in Six (6) different angles with the case number each shot.
1. Front view, whole body.
2. Front view (half body-head to elbow) 3. Left Side view (half body-head to elbow)
4. Right side view (half body –head to elbow)
5. Left Quarter view (half body-head to elbow)
6. Right Quarter view (half body-head to elbow) PHOTOGRAPHING LIVE VICTIMS AND SUSPECTS
Photographs that show area of the body which usually are not visible when the person is clothed should be taken ONLY under the direct supervision of the examining physician or nurse, whose testimony the photographs are intended to illustrate. Thus, it is unusual that this type of photograph will be taken on a crime scene.
Before photographing any part of the female body normally covered by clothing, written consent of the subject must be obtained. If the subject is a minor, the written consent of the parent is needed and the photography must be done with witnesses present.
REMEMBER: Only take photographs of the area that needs to be documented. The Basic Technique in holding the 35mm camera:
1. Hold the camera with the right hand placing the index finger under the shutter release, thumb under the film advance lever and the remaining three fingers against the front of the camera.
2. The hill of the camera must lie on the palm of the left hand.
3. The placement of the rest of the body while taking the photograph is as important as holding the camera.
The photographer’s arm should be resting against the body with the legs far enough apart to be a steady base. When taking a photograph in a kneeling position, do not rest the elbow on the knees as the bone-to-bone contact is unsteady and will be reflected in the photograph.
Six (6) steps used to load film into a 35mm camera and the three (3) steps used to unload film from a 35mm camera.
Loading and Unloading the 35mm:
A. Loading Film
To load the film into a 35mm camera:
1. Open the back of the camera by lifting the film rewind knob and pulling out the back. 2. With the rewind knob up, fit the film canister on the left side under the rewind knob. 3. Push the tail of the film gently out of the canister into place. 4. Pull the tail of the film gently out of the canister and insert it into the take-up spool. 5. Turn the rewind knob slightly to make sure that the film is snug against the sprockets and advance the film once. 6. Close the camera and advance the film twice. B. Unloading Film
To unload the film into a 35mm camera:
1. Release the take-up spool by pushing the film rewind button on the bottom of the camera. 2. Pull the rewind lever out and turn it slowly until it is released from the take-up spool. 3. Turn the lever a few more times and then open the back of the camera and remove the canister.
Different Types of Lenses
ZOOM LENS- allows you to fine-tune subject framing by adjusting the focal length of the lens.
STANDARD ZOOM LENS produces an image that is roughly equivalent to the way a scene appears when viewed with the naked eye. It often have wide maximum apertures, making them useful in low-light situation.
WIDE-ANGLE ZOOM can able to select an intermediate focal length setting. However, it is likely to be slower and heavier and to show more image distortion than a wide-angle fixed focal length lens.
WIDE-ANGLE LENS takes in larger angle of view than a standard lens, and is ideal for photographing a group of people or when you are working in confined space.
ZOOM LENS with variable focal length that can be quickly adjusted to varying subject or image size.
TELEPHOTO ZOOM LENS is useful for portraits and for moving objects. Unlike a wide-angle zoom, a telephoto zoom should not show any obvious distortion.
SHIFT LENS (also known as Perspective Control Lens) gets its name because it can be shifted off-centered in relation to the film frame. You can keep the camera parallel and shift the lens upward to record an undistorted image.
APPLICATION OF PHOTOGRAPHY TO LAW ENFORCEMENT Uses of Photography:
1. Identification of the Subject.
The first step in investigation in any crime is to photograph all aspects of the crime scene completely and accurately before any of the objects of evidence is removed or otherwise distributed.
We produce pictorial record of everything regarding the crime to include the nearby surroundings. It is always better to take too many photographs than too few then select the best.
2. Preservation of Evidence.
Prevent from necessary handling of physical evidence thus preserving the integrity of the physical evidence.
3. Description of the Crime Scene.
It proves statement. In some instances, investigators are compelled to reconstruct or describe in court the details of the crime scene they have investigated several months ago but with the bulk of the case they handled perhaps they may not exactly recall. With the aid of photographs, investigators will not find hard time to describe things in detail.
USES OF PHOTOGRAPHS IN POLICE WORK
1. It refreshes the mind of the investigator. -It is a sort of artificial memory.
2. It is useful in personal identification as well as in the identification of missing person, identification of stolen and lost properties.
3. It provides a second look and often reveals detail that is not apparent during the physical examination.
4. It records all things that an investigator may fail to notice.
5. It makes the accused admit his crime.
-The photographs help in securing or obtaining confession.
-The guilty party may sometimes confess when confronted with relevant photographs. -Refusal of the accused to look at the gruesome pictures of the victim and the crime scene, the court considered it as evidence of guilt.
6. It assists the court in understanding their findings.
7. It helps reconstruct crime scene.
8. It helps the expert witness in illustrating their findings.
9. Photographs are used to supplement, explain, and replace the descriptive testimony of witnesses.
10. It serves as lecture materials and illustrations during police personnel training.
11. It is also used to reproduced and copy documents.
Night Photography
EXPOSURE (with available light)
In addition to the direction of the light, you must also consider the amount of light. This is governed by “exposure”.
Modern cameras with automatic metering system can greatly simplify exposure problems, especially when you have to shoot quickly. Nevertheless, no camera can “think” for you. The photographer is ultimately responsible for the exposure. Your Nikon FM2 camera has a built-in exposure meter. In most cases, “centering the exposure needle” is all that is required. Do not take photographs looking into the sun. The exposure meter will be fooled by the light.
STEPS TO FOLLOW TO OBTAIN PROPER EXPOSURE
(Using available light photography)
1. When inserting a roll of film in the camera, you must always set your ASA dial according to the film speed as stated on the film cartridge. This adjusts your built-in light meter to the film’s light sensitivity.
2. For crime or accident scenes, the shutter speed on the camera should be set at 1/125 sec. This is usually a good starting point for the shutter speed. Your shutter speed could change from a slower speed to a faster one depending on the light intensity at the time the photograph is taken. 3. Adjust your light meter needle as seen in the viewfinder by turning the aperture ring located on the barrel of the lens until the needle is properly lined up. When the needle is properly lined up, this tells that the photographer that the light entering the camera will produce a properly exposed photograph.
4. Your final step in available light photography is to COMPOSE and FOCUS.
NB: Use a shutter speed faster than 1/30 of a second for all hand held photographs. The camera must be supported (tripod, etc.) for shutter speed of 1/30 of a second or slower.
Crime Scene Photography
Procedure in photographing the crime scene:
The goal is to record useful information in a series of photographs which will enable the viewer to understand where end how the crime was committed. The term “crime scene” not only refers to the immediate as where important acts took immediately before or after the crime was committed.
Photographs of the broad area of the crime scene should be supplemented by closer shots of sections containing important detail. Each area or object should be photographed so that it can be located readily in the overall pictures, which will enable the viewer to gain a clear concept of this position with reference to other objects at the scene.
These locations will enable the viewer of the pictures to orient the crime scene in logical manner.
1. General View or Long-Range General View or Long-range photographs of the overall scene fundamentally are taken to portray the areas as if a person viewing the scene is seeing it from the standing position. To obtain this result, the photographer takes the photograph with the camera at eye level.
2. Medium View or Mid-range Medium view or Mid-range photographs are taken in a manner which portrays the scene from approximately ten to twenty feet of distance from the subject matter. In order that the viewer be permitted to associate the crime scene with separate areas of the scene photographed, these areas should contain sufficient detail to permit the viewer this association. 3. Close-up View/Range Close-up range photographs are normally taken approximately five feet or less from the subject matter. The attention of close-up photography is directed to objects which could not effectively be seen in the long- range and mid-range photographs.
Take necessary extreme close-up shot on the subject to show the extent damage.
Two General Methods of Photography
1. Overlapping Method- A photographic method of taking a series of photographs in a circular or clockwise direction, overlapping each other slightly to show the entire crime scene. If a single photograph cannot show the entire crime scene, apply this method. 2. Progressive Method- A photographic method of taking a crime scene photographs starting from a fixed point, photographing each piece of evidence as the photographer moves toward it, and progressively gets closer.(from general to specific)
Sequential Photographs of the Crime Scene
Each crime scene has individual features that should be photographed. Keep in mind the nature of the offense and try to show those features that establish the elements of the offense. Photographs should be taken of:
1. Views of the exterior of the building/vehicle, with relation to other buildings/vehicles, roads streets, etc. 2. Point of entry, outside and inside. 3. Point of exit, outside and inside 4. Condition(s) of the crime scene. 5. Area in which valuable articles were removed. 6. Articles left at the scene. 7. Trace evidence, such as hairs, fibers, and cigarrete butts. 8. Tool marks and impressions of shoes or tore trucks. 9. Fingerprints and footprints, as well as articles on which this prints may be found.
Categorizing Photo Evidence The investigator must make a written record of what is recorded on film. The first frame of the crime scene photographs should be a photograph of chalk slate or a piece of paper, preferably the size of a piece of notebook paper that contains information identifying the case. This information should include the name of the photographer, the name of the victim, the address, date, case number and time. By including this information or misdirected by the photo lab will be lessened. The following should also be recorded in the photographer’s note.
1. Location’s address, date and time 2. Type of incident and objects photographed. 3. Type of film used and number of exposure. 4. Type of camera used. 5. Name of investigator on case/photographer. 6. Names of victims and witnesses. 7. Chain of custody. 8. Weather condition.
The chain of custody of the photographs must be maintained. The film should be removed from the camera and taken directly to processing unless some secure facility is available for overnight storage. If this does not occur, the judge or jury may disregard this most important evidence under the theory that the film may have been tampered with.
Preservation of Fingerprint through Photographs
When possible, fingerprints found at the crime scene should be preserved by photography before any attempts are made at preserving them. The photographer must be skilled in photographic techniques and understand how to obtain a reproduction of a fingerprint as accurate and true to the original as possible. Photographing a print leaves the object intact so that further photos can be taken if the first are unsuccessful. It also makes it easier to produce the evidence in court. If prints are lifted, the object on which they were discovered can be seen in the picture.
Marking in the Field of View
Measuring devices such as rulers, yardsticks, and tape measures should be used to show the relative size of, and distance between objects, or the degree of magnification of the enlargement. The markers should be place beside the object in a manner that will obscure any important piece of evidence. In document and small object photographs, a six inch ruler placed at the bottom or just below the item of evidence will enable the photographer to determine the degree of enlargement quickly and also show the relative size of objects in the photographic exhibit. Many times, court objects to the use of rilers and marking devices that appear in photographs of a crime scene. Therefore, photographs should be taken in two ways:
1. First, without markers so as not to tamper the evidence. 2. Second, with marker to show its size or its continuity.
1. Wide Angle Lenses Traditionally, a super wide-angle lens is classified as anything under 20mm. Wide- angle is 21-35mm. With the advent of digital cameras, and the APS-C format, camera manufacturers have also started producing specific lenses for this format. Wide-angle lenses for crop frame DSLRs range from 10-24mm, with a few going down to a super wide 8mm.
Wide-angle lenses are most commonly used for photographing landscapes and architecture, although they are often also used for photographing large groups of people. The Tokina AT-X 116 Pro DX lens (pictured here) is an example of a wide-angle lens (11-16mm). More » Read Review Ads Long Valley Equipment longvalleyequip.com Camera Jibs, Dollies with track Nikon mount for Epic and Scarlet
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PriceGrabber 2. Standard Lenses A standard lens has a focal length range of 35-70mm. The most common standard lens is a fixed 50mm lens.
Standard lenses are most commonly used for documentary and street photography, where photographers need to move quickly and capture an interesting point of action. Pioneers of modern street photography, such as Henri Cartier-Bresson, always used a 50mm lens, choosing to move themselves around so as to best frame an image.
The Nikon 50mm f1.8D lens (pictured here) is an example of a standard, fixed lens. More » Read Review
PriceGrabber 3. Medium Telephoto / Portrait Lens The focal range between 80-135mm is nearly always used by portrait photographers. Fixed lenses at these lengths produce ideal framing for head and shoulders shots. These are specialist lenses, but can be surprisingly reasonably priced.
The Canon EF 100mm F/2.8 Macro USM lens is an example of a one of these types of lenses. More » Read Review Ads Hide Your IP Free/Win OS proxyrental.net/Hide-Your-IP NO Shared IPs - Never Get Blocked! Download our 100% Free software NOW
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Telephoto lenses are traditionally used for sports and wildlife photography, but their essential function is to bring distant objects closer.
One example of a telephoto lens is the Canon EF 200mm f/2L IS USM telephoto lens pictured here. More »
PriceGrabber 5. Specialist Lenses There are a variety of specialist lenses available. Some of the more common are:
Super Telephoto. These have a focal length of more than 300mm, and are used by dedicated sports and wildlife photographers. The Nikon AF-S Nikkor 400mm f/2.8G super telephoto lens (pictured here) is an example.
Macro. These lenses are able to focus closer to an object than normal lenses, offering a 1:1 ratio. They are used for still-life photography of small objects. Fisheye. These are on the edge of wide-angle lenses, and give a distorted view of the subject matter. The center of the image is magnified, and objects diminish in size in all directions around it. More » Three (3) Pillars of Photography
1. What is Aperture? Simply put, aperture is a hole within a lens, through which light travels into the camera body. It is easier to understand the concept if you just think about our eyes. Every camera that we know of today is designed like human eyes. The cornea in our eyes is like the front element of a lens – it gathers all external light, then bends it and passes it to the iris. Depending on the amount of light, the iris can either expand or shrink, controlling the size of the pupil, which is a hole that lets the light pass further into the eye. The pupil is essentially what we refer to as aperture in photography. The amount of light that enters the retina (which works just like the camera sensor), is limited to the size of the pupil – the larger the pupil, the more light enters the retina. So, the easiest way to remember aperture, is by associating it with your pupil. Large pupil size equals large aperture, while small pupil size equals small aperture.
Size of Aperture – Large vs Small Aperture The iris of the lens that controls the size (diameter) of the aperture is called “diaphragm” in optics. The sole purpose of the diaphragm is to block or stop all light, with the exception of the light that goes through the aperture. In photography, aperture is expressed in f-numbers (for example f/5.6). These f-numbers that are known as “f-stops” are a way of describing the size of the aperture, or how open or closed the aperture is. A smaller f-stop means a larger aperture, while a larger f-stop means a smaller aperture. Most people find this awkward, since we are used to having larger numbers represent larger values, but not in this case. For example, f/1.4 is larger than f/2.0 and much larger than f/8.0. Take a look at this chart (image courtesy of Wikipedia):
The size of the circle represents the size of the lens aperture – the larger the f- number, the smaller the aperture.
2) What is Shutter Speed? Shutter speed, also known as “exposure time”, stands for the length of time a camera shutter is open to expose light into the camera sensor. If the shutter speed is fast, it can help to freeze action completely, as seen in the above photo of the dolphin. If the shutter speed is slow, it can create an effect called “motion blur”, where moving objects appear blurred along the direction of the motion. This effect is used quite a bit in advertisements of cars and motorbikes, where a sense of speed and motion is communicated to the viewer by intentionally blurring the moving wheels. Shutter Speed is one of the three pillars of photography, the other two being ISO and Aperture. Shutter speed is where the other side of the magic happens – it is responsible for creating dramatic effects by either freezing action or blurring motion. In this article, I will try to explain everything I know about shutter speed in very simple language. The button that fires the camera is also called “shutter” or “shutter button”, because it triggers the shutter to open and close.
How shutter speed is measured
Shutter speeds are typically measured in fractions of a second, when they are under a second. For example 1/4 means a quarter of a second, while 1/250 means one two-hundred-and-fiftieth of a second or four milliseconds. Most modern DSLRs can handle shutter speeds of up to 1/4000th of a second, while some can handle much higher speeds of 1/8000th of a second and faster. The longest shutter speed on most DSLRs is typically 30 seconds (without using external remote triggers).
Fast, slow and long shutter speeds Fast shutter speed is typically whatever it takes to freeze action. For me, it is typically above 1/500th of a second for general photography and above 1/1000th of a second for bird photography. How about long shutter speed? Long shutter speeds are typically above 1 second, when you have to use a tripod to get acceptably sharp images (for low-light/night photography or to capture movement).
How to set shutter speed
Most cameras handle shutter speeds automatically through in-camera metering. When the camera is set to “Auto” mode, both shutter speed and aperture are automatically selected by the camera. When you shoot in “Aperture Priority” mode, you set the lens aperture, while the camera automatically sets the shutter speed. There are two ways to manually set the shutter speed: a) By setting the camera to “Shutter Priority” mode, where you set the shutter speed and the camera automatically selects the aperture. b) By setting the camera to “Manual” mode, where you set both shutter speed and aperture manually. I recommend letting the camera select the correct shutter speed for you. I personally shoot in “Aperture Priority” mode 99% of the time and I let my camera calculate the shutter speed for me.
How to find shutter speed Do you know how to find out what your camera shutter speed is set to? It is typically very easy to find the shutter speed. On Nikon DSLRs that have a top panel, the shutter speed is typically located on the top left corner:
If you look through the viewfinder, it should also be the number on the bottom left side of the screen. On most DSLRs, you will not see the shutter speed as a fraction of a second – it will typically be a regular number. When the shutter speed is slower than or equals to one second, you will see something like 1″ or 5″ (the ” sign indicates a full second). If you still can’t find the shutter speed, set your camera to “Aperture Priority” mode, then look into the viewfinder and point at a really dark area. Remember the numbers in the display, then switch to a very bright area and see what number changes. The number that changes is your shutter speed.
3) What is ISO?
In very basic terms, ISO is the level of sensitivity of your camera to available light. The lower the ISO number, the less sensitive it is to the light, while a higher ISO number increases the sensitivity of your camera. The component within your camera that can change sensitivity is called “image sensor” or simply “sensor”. It is the most important (and most expensive) part of a camera and it is responsible for gathering light and transforming it into an image. With increased sensitivity, your camera sensor can capture images in low-light environments without having to use a flash. But higher sensitivity comes at an expense – it adds grain or “noise” to the pictures. The difference is clear – the image on the right hand side at ISO 3200 has a lot more noise in it, than the one on the left at ISO 200. Every camera has something called “Base ISO“, which is typically the lowest ISO number of the sensor that can produce the highest image quality, without adding noise to the picture. On most of the new Nikon cameras such as Nikon D5100, the base ISO is typically 200, while most Canon digital cameras have the base ISO of 100. So, optimally, you should always try to stick to the base ISO to get the highest image quality . However, it is not always possible to do so, especially when working in low-light conditions. Typically, ISO numbers start from 100-200 (Base ISO) and increment in value in geometric progression (power of two). So, the ISO sequence is: 100, 200, 400, 800, 1600, 3200, 6400 and etc. The important thing to understand, is that each step between the numbers effectively doubles the sensitivity of the sensor. So, ISO 200 is twice more sensitive than ISO 100, while ISO 400 is twice more sensitive than ISO 200. This makes ISO 400 four times more sensitive to light than ISO 100, and ISO 1600 sixteen times more sensitive to light than ISO 100, so on and so forth. What does it mean when a sensor is sixteen times more sensitive to light? It means that it needs sixteen times less time to capture an image! ISO Speed Example: ISO 100 – 1 second ISO 200 – 1/2 of a second ISO 400 – 1/4 of a second ISO 800 – 1/8 of a second ISO 1600 – 1/16 of a second ISO 3200 – 1/32 of a second
In the above ISO Speed Example, if your camera sensor needed exactly 1 second to capture a scene at ISO 100, simply by switching to ISO 800, you can capture the same scene at 1/8th of a second or at 125 milliseconds! That can mean a world of difference in photography, since it can help to freeze motion.
When to increase ISO
You should increase the ISO when there is not enough light for the camera to be able to quickly capture an image. Anytime I shoot indoors without a flash, I set my ISO to a higher number to be able to freeze motion. Other cases where you might want to increase ISO are when you need to get ultra-fast shots, like the bird picture I posted above. But before increasing the ISO, you should think if it is OK for you to introduce noise to the image. On many of the newer DSLRs, there is a setting for “Auto ISO”, which works great in low-light environments. The beauty of this setting, is that you can set the maximum ISO to a certain number, so when the ISO is automatically increased based on the amount of light, it does not cross the set barrier. So, if I want to limit the amount of grain in my pictures, I typically set the maximum ISO to 800. If you have any questions, comments or feedback, please post them in the comments section below. Please note that the above explanation of ISO is given in very basic/simple terms, similar to film sensitivity. Correctly defining ISO in digital cameras can get fairly complex. If you want to find out more about ISO in digital cameras, including the ISO 12232:2006 standard, please see this article from Wikipedia.
What is Depth of Field? One important thing to remember here, the size of the aperture has a direct impact on the depth of field, which is the area of the image that appears sharp. A large f-number such as f/32, (which means a smaller aperture) will bring all foreground and background objects in focus, while a small f-number such as f/1.4 will isolate the foreground from the background by making the foreground objects sharp and the background blurry.
In the above example, due to the shallow depth of field, only the word “Cougar” appears sharp, while everything else in the front and behind of that word is blurred. If I had used a larger aperture such as f/1.4 and focused on one of the letters, probably only that letter would have been sharp, while everything else would have been blurred out. The larger the aperture, the smaller the area in focus (depth of field).
Is the distance measured from the nearest to the farthest object in apparent sharp focus when the lens is set or focus at a particular distance.
The term Depth of Field is used to describe how much of what the camera sees in focus.
Also known as the ZONE OF FOCUS
Smaller Opening-Shallow depth of field
Higher Opening- Narrower EXPOSURE Combinations
THE TWO (2) ADJUSTMENTS ON A CAMERA THAT CONTROLS THE AMOUNT OF LIGHT THAT REACHES THE FILM. What is Over and Under Exposure?
UNDEREXPOSURE – A condition in which too little light reaches the film, producing a thin negative, S standing for short exposure
OVEREXPOSURE – Excessive amount of light falling on the sensitized material during exposure resulting in dense negative with opaque highlights or prints with blocked up shadows and veiled highlights.
STEPS TO FOLLOW TO OBTAIN PROPER EXPOSURE
(Using available light photography)
1. When inserting a roll of film in the camera, you must always set your ASA dial according to the film speed as stated on the film cartridge. This adjusts your built-in light meter to the film’s light sensitivity.
2. For crime or accident scenes, the shutter speed on the camera should be set at 1/125 sec. This is usually a good starting point for the shutter speed. Your shutter speed could change from a slower speed to a faster one depending on the light intensity at the time the photograph is taken.
3. Adjust your light meter needle as seen in the viewfinder by turning the aperture ring located on the barrel of the lens until the needle is properly lined up. When the needle is properly lined up, this tells that the photographer that the light entering the camera will produce a properly exposed photograph. 4. Your final step in available light photography is to COMPOSE and FOCUS.
NB: Use a shutter speed faster than 1/30 of a second for all hand held photographs. The camera must be supported (tripod, etc.) for shutter speed of 1/30 of a second or slower.