SensualEye Photography Glossary

Aberration An optical defect in a lens causing it to form an image that is not sharp or that is distorted.

Additive color A way to produce colors of light by mixing light of the three additive primary colors; red, green, and blue. Varying proportions of the additive primaries can be combined to create light of all other colors, including white, which is a mixture of all wavelengths.

AE See auto exposure.

AF See auto focus.

Agitate To move a solution over the surface of film or paper during development so that fresh liquid comes into contact with the surface.

Angle of view The area seen by a lens or view-finder or read by a light meter.

Aperture The size of the lens opening through which light passes. The relative aperture is measured as the focal length of the lens divided by the diameter of the aperture; this is expressed as an f/stop number: f/8, f/I 1, and so on.
aperture of a 50mm lens

Aperture-priority A mode of auto exposure in which the photographer selects the aperture and the camera sets the shutter speed that will produce the correct exposure.

Archival processing Processing designed to pro-tect a print or negative as much as possible from premature deterioration caused by chemical reactions.

Artificial light Light from an electric lamp, a flash bulb, or electronic flash. Often describes lights that the photographer has set up to illuminate a scene.

ASA rating A numerical rating system that describes the sensitivity of a film to light.

Auto exposure A camera function in which the camera adjusts the shutter speed, the aperture, or both to produce correct exposure. Abbreviated AE.

Auto flash An electronic flash unit with a light-sensitive cell and electronic circuitry that measures the light reflected back from the subject and ends the flash when the exposure is correct.

Auto focus A system by which the camera adjusts its lens to focus on a given area, for example, whatever is at the center of the image. Abbreviated AF.

Ambient light See available light.

Av Abbreviation of aperture value. Used on some camera information displays as a shortened way to refer to aperture settings (f/stops).

Available light The light that already exists in a scene where a photograph is to be made, as opposed to light brought in by the photographer(i.e. flash, strobe or lights). Often implies a relatively dim light. Also called ambient light or existing light.

Axis lighting Light pointed at the subject from a position close to the camera's lens. This often causes red eye in your pictures.

B See bulb.

Backlit / Backlighting Light that comes from behind the subject toward the camera.

Barrel distortion A lens aberration or defect that causes straight lines to bow outward, away from the center of the image.

Bellows A flexible, light-tight and usually accor-dion-folded part of a view camera between the lens board in front and the viewing screen in back. Also used on a smaller camera when the lens must be positioned farther than normal from the film(i.e. macrophotography).

Blocked up Describes highlight areas that lack normal texture and detail. Due to excess con-trast caused by, for example, overexposure or overdevelopment.

Blotter A sheet of absorbent paper made expressly for photographic use. Wet prints dry when placed between blotters.

Bounce light Light that does not travel directly from its source to the subject but is first reflected off another surface.

Bracket To make several exposures, some greater and some less than the exposure that is calculated to be correct. Bracketing allows for error and permits selection of the best exposure after development.

Brightness A subjective impression of the lightness of an object. A measurable quantity of light reflected or produced by an object is luminance. See luminance.

Broadlighting Portrait lighting in which the main source of light illuminates the side of the face turned most toward the camera.

Built-in meter A reflected-light exposure meter built into a camera so that light readings can be made directly from the camera position.
Bulb A shutter setting marked B at which the shutter remains open as long as the shutter release is held down.

Burn in To darken a specific area of a print by giving it additional exposure.

Butterfly lighting Portrait lighting in which the main source of light is placed high and directly in front of the face.

Cable release A long wire with a plunger at one end and a socket at the other that attaches to a camera's shutter release. Pressing the plunger releases the shutter without touching (and possibly moving) the camera.

Camera

Camera obscure Latin for "dark chamber": a darkened room with a small opening through which rays of light could enter and form an image of the scene outside. Eventually, a lens was added at the opening to improve the image, and the room shrank to a small, portable box.

Cartridge See cassette.

Cassette A light-tight metal or plastic container that permits a roll of 35mm film to be loaded into a camera in the light. Also called a cartridge.

Catchlight Reflections of a light source in a sub-ject's eye.
Changing bag A light-tight bag into which a pho-tographer can insert his or her hands to handle film when a darkroom is not available.

Characteristic curve A diagram of the response to light of a photographic material, showing how increasing exposure affects silver density during development. Also called the D log E curve, since density is plotted against the logarithm of the exposure.

Chromatic aberration A lens defect that bends light rays of different colors at different angles and therefore focuses them on different planes.

Chrome A color transparency film.

Chromogenic film Film in which the final image is composed of dyes rather than silver.

Circle of confusion The tiny circle of light formed by a lens as it projects the image of a single point of a subject. The smaller the diameters of all the circles of confusion in an image, the sharper the image will be.

Close-up image A larger-than-normal image that is formed on a negative by focusing the subject closer than normal to the lens with the use of supplementary lenses, extension tubes, or bel-lows.

Close-up lens See supplementary lens.

Colorcast A trace of one color in lithe colors in an image.

Color compensating filters Glass or gelatin filters that can be used to adjust the color balance during picture taking or in color printing. More expen-sive than acetate color printing filters, they can be used below the enlarger lens if the enlarger has no other place for filters. Abbreviated CC fil-ters.

Color printing filters Acetate filters used to adjust the color balance in color printing. They must be used with an enlarger that can hold filters between the enlarger lamp and the negative. Abbreviated CP filters.

Color temperature A numerical description of the color of light. It is the temperature in degrees Kelvin (K) to which a perfect black-body radiator (an object that does not reflect any light failing on it) would have to be heated to produce a given color.

Color temperature meter A device for estimating the color temperature of a light source. Usually used to determine the filtration needed to match the color balance of the light source with that of standard types of color film.

Coma A lens aberration or defect that causes rays that pass obliquely through the lens to be focused at different points on the film plane.

Complementary colors 1) Any two colors of light that when combined include all the wavelengths of light and thus produce white light (see additive color). 2) Any two dye colors that when com-bined absorb all wavelengths of light and thus produce black (see subtractive color). A colored filter absorbs light of its complementary color and passes light of its own color.

Condenser enlarger An enlarger that illuminates the negative with light that has been concentrated and directed by condenser lenses placed between the light source and the negative.

Contact printing The process of placing a nega-tive in contact with sensitized material, usually paper, and then passing light through the nega-tive onto the material. The resulting image is the same size as the negative.

Continuous tone Describes an image with a smooth gradation of tones from black through gray to white.

Contrast The difference in darkness or density between one tone and another.

Contrast filter A colored filter used on a camera lens to lighten or darken selected colors in a black-and-white photograph. For example, a green filter used to darken red flowers against green leaves.

Contrast grade The contrast that a printing paper produces. Systems of grading contrast are not uniform, but in general grades 0 and 1 have low or soft contrast; grades 2 and 3 have normal or medium contrast; grades 4, 5, and 6 have high or hard contrast.

Contrasty Describes a scene, negative, or print with very great differences in brightness between light and dark areas. Opposite: flat.

Convergence The phenomenon in which lines that are parallel in a subject, such as the vertical lines of a building, appear nonparallel in an image.

Cool Refers to bluish colors that, by association with common objects (water, ice, and so on), give an impression of coolness.

Correction filter A colored filter used on a camera lens to make black-and-white film produce the same relative brightness as perceived by the human eye. For example, a yellow filter used to darken a blue sky so it does not appear excessively light.

Coupled rangefinder See rangefinder.

Covering power The area of the focal plane over which a lens projects an image that is acceptably sharp and uniformly illuminated.

Crop To trim the edge so fan image, often to improve the composition. Cropping can be done by moving the camera position while viewing a scene, by adjusting the enlarger or easel during printing, or by trimming the finished print.

Curvilinear distortion See barrel distortion, pin-cushion distortion.

Cut film See sheet film.

Daguerreotype The first practical photographic process, invented by Daguerre and described by him in 1839. The process produced a positive image formed by mercury vapor on a metal plate coated with silver iodide.

Darkroom A room where photographs are devel-oped and printed, sufficiently dark to handle light-sensitive materials without causing unwanted exposure.

Dark slide See slide (2).

Daylight film Color film that is balanced to pro-duce accurate color renditions when the light source illuminating the photographed scene has a color temperature of about 5500K, such as in midday sunlight or with electronic flash or a blue flashbulb.

Dedicated flash An electronic flash unit that, when used with certain cameras, will automati-cally set the correct shutter speed for use with flash and will trigger a light in the viewfinder when the flash is charged and ready to fire. Also called designated flash.

Dense Describes a negative or an area of a nega-tive in which a large amount of silver has been deposited. A dense negative transmits relatively little light. Opposite: thin.

Densitometer An instrument that measures the darkness or density of a negative or print.

Density The relative amount of silver present in various areas of film or paper after exposure or development. The darkness of a pho-tographic print or the light-stopping ability of a negative or transparency.

Depth of field The area between the nearest and farthest points from the camera that are accept-ably sharp in an image.

Depth of focus The small range of allowable focusing error which will still produce an accept-ably sharp image when a lens is not focused exactly.

Designated flash See dedicated flash.

Developer A chemical solution that changes the invisible, latent image produced during expo-sure into a visible one.

Development 1) The entire process by which exposed film or paper is treated with various chemicals to make an image that is visible and permanent. 2) Specifically, the step in which film or paper is immersed in developer.

Diaphragm The mechanism controlling the brightness of light that passes through a lens. An iris diaphragm has overlapping metal leaves whose central opening can be adjusted to a larger or smaller size. See aperture.

Dichroichead An enlarger head that contains yellow, magenta, and cyan filters that can be moved in calibrated stages into or out of the light beam to change the color balance of the enlarging light.

Diffuse Scattered, not all coming from the same direction. For example, sunlight on a cloudy day

Digital imaging A method of image capturing in which a picture is reduced to digital information that can be read and manipulated by a computer, and subsequently reformed as a visible image.

DIN A numerical rating used in Europe to describe the sensitivity of film to light. The DIN rating increases by 3 as the sensitivity of the film doubles.

Diopter An optician's term to describe the power of a lens. In photography, it mainly indicates the magnifying power and focal length of a supplementary close-up lens.

Distortion 1) A lens aberration that causes straight lines at the edge of an image to appear curved. 2) The changes in perspective that take place when a lens is used very close to (wide -angle effect) or very far from (telephoto effect) a subject.

Dodge To lighten an area of a print by shading it during part of the printing exposure.

Dropout An image with black and white areas only and no intermediate gray tones. Usually made by using high-contrast lith film.

Dry down To become very slightly darker and less contrasty, as most photographic printing papers do when they dry after processing.

Dry mount To attach a print to another surface, usually cardboard, by placing a sheet of dry-mount tissue between the print and the mount-ing surface. This sandwich is placed in a heated mounting press to melt an adhesive in the tissue.

DX coding A checkered or barcode on some film cassettes. The checkered code can be automatically scanned by a suitably equipped camera for such information as film speed and number of frames. The bar code is read by automatic film processing equipment for film type, processing procedure, and so on.

Easel A holder to keep sensitized material, nor-mally paper, flat and in position on the baseboard of an enlarger during projection printing. It usually has adjustable borders to frame the image to various sizes.

El See exposure index.

Electromagnetic spectrum The forms of radiant energy arranged by size of wavelength ranging from billionths of a millimeter (gamma rays) to several miles (radio waves). The visible spectrum is the part that the human eye sees as light: wavelengths of 400 to 700 manometers (bil-lionths of a meter), producing the sensation of the colors violet, blue, green, yellow, and red.

Electronic flash A tube containing gas that pro-duces a brief, brilliant flash of light when electri-fied. Unlike a flashbulb, an electronic flash unit is reusable. Also called a strobe.

Emulsion A light-sensitive coating applied to photographic films or papers. It consists of silver halide crystals and other chemicals suspended in gelatin.

Enlargement An image, usually a print, that is larger than the negative. Made by projecting an enlarged image of the negative onto sensitized paper.

Enlarger An optical instrument ordinarily used to project an image of a negative onto sensitized paper. More accurately called a projection printer because it can project an image that is either larger or smaller than the negative.

Etch To remove a small, dark imperfection in a print or negative by scraping away part of the emulsion.

EV See exposure value.

Existing light See available light.

Exposure 1) The act of letting light fall on a light -sensitive material. 2) The amount of light reach-ing the light-sensitive material; specifically, the intensity of light multiplied by the length of time it falls on the material.

Exposure index A non-standard film speed rating similar to an ISO/ASA rating. Abbreviated El.

Exposure latitude The amount of over or underexposure possible without a significant loss in the quality of an image.

Exposure meter An instrument that measures the amount of light falling on a subject (incident -light meter) or emitted or reflected by a subject (reflected-light meter), allowing aperture and shutter speed settings to be computed. Commonly called a light meter.
Incident light meter

Exposure value A system originally intended to simplify exposure calculations by assigning standardized number values to f-stop and shutter speed combinations. More often, used simply as a shorthand way of describing the range of light levels within which equipment operates. For example, a manufacturer may describe a meter as operating from EV -1 to EV 20 (4 sec at f/1.4 to 1/2000 sec at f/22, with ISO/ASA I 00 film).

Extension tubes Metal rings that can be attached between a camera body and lens for close-up work. They extend the lens farther than normal from the film plane so that the lens can focus closer than normal to an object.

Factor A number that tells how many times exposure must be increased to compensate for loss of light (for example, due to use of a filter).

Farmer's reducer A solution of potassium ferricyanide and sodium thiosulfate that is used to decrease the amount of silver in a developed image.

Fast Describesl)afilmorpaperthatisverysen-sitive to light; 2) a lens that opens to a very wide aperture; 3) a short shutter speed. Opposite: slow.

Field curvature A lens aberration or defect that causes the image to be formed along a curve instead of on a flat plane.

Fill light A source of illumination that lightens shadows cast by the main light and there by reduces the contrast in a photograph.

Film The material used in a camera to record a photographic image. Generally it is a light-sensitive emulsion coated on a flexible acetate or plastic base.

Film holder A light-tight container to hold the sheet film used in a view camera.
filmplane Seefocalplane.

Film speed The relative sensitivity to light of a film. There are several rating systems: ISO/ASA (the most common in the United States and Great Britain), DIN (common in Europe), and others. Film speed ratings increase as the sensi-tivity of the film increases.

Filter 1) A piece of colored glass, plastic, or othei material that selectively absorbs some of the wavelengths of light passing through it. 2) To use such a filter to modify the wavelengths of light reaching a light-sensitive material. filter factor See factor.

Fisheye lens A lens with an extremely wide angle of view (as much as 180') and considerable bar-rel distortion (straight lines at the edges of a scene appear to curve around the center of the image).
Fish-eye photo

Fixer A chemical solution(sodium thiosulfate or ammonium thiosulfate) that makes a photographic image insensitive to light. It dissolves unexposed silver halide crystals while leaving the developed silver image. Also called hypo.

Flare Unwanted light that reflects and scatters inside a lens or camera. When it reaches the film, it causes a loss of contrast in the image.

Flash I)A light source, such as a flash bulb or electronic flash, that emits a very brief, bright burst of light. 2) To blacken an area in a print by exposing it to white light, such as from a pan-light flashlight.

Flashbulb Abulbcontainingamassofaluminum wire, oxygen, and an explosive primer. When the primer is electrically fired, it ignites the wire which emits a brief burst of brilliant light. A flashbulb is used once and then discarded.

Flashmeter An exposure meter that measures the brightness of flash lighting to determine the correct exposure for a particular setup.

Flat 1) A scene, negative, or print with very little difference in brightness between light and dark areas. Opposite: contrasty. 2) See reflector.

Floodlight An electric light designed to produce a broad, relatively diffused beam of light.

F-number A number that equals the focal length of a lens divided by the diameter of the aperture at a given setting. Theoretically, all lenses at the same f-number produce images of equal brightness. Also called f-stop or relative aperture.

Focal length The distance from the lens to the focal plane when the lens is focused on infinity. The longer the focal length, the greater the magnification of the image.

Focal plane The plane or surface on which a focused lens forms a sharp image. Also called the film plane.

Focal-plane shutter A camera mechanism that admits light to expose film by moving a slit or opening in a roller blind just in front of the film (focal) plane.

Focal point The point on a focused image where the rays of light intersect after reflecting from a single point on a subject.

Focus 1)Thepositionatwhichraysoflightfroma lens converge to form a sharp image. 2) To adjust the distance between lens and image to make the image as sharp as possible.

Focusing cloth A dark cloth used in focusing a view camera. The cloth fits over the camera back and the photographer's head to keep out light and to make the ground-glass image easier to see.

Fog An overall density in the photographic image caused by unintentional exposure to light or unwanted chemical activity.

Frame 1)Theedgesofanimage. 2)Asingle image in a roll of film.

F-stop The common term for the aperture setting of a lens. See f-number.

Full-scale Describes a print having a wide range of tonal values from deep, rich black through many shades of gray to brilliant white.

Illuminance The strength of light falling on a given area of a surface. Measurable by an incident light (illuminance) meter. illuminance meter See incident light meter.

Incandescent light Light emitted when a substance is heated by electricity: for example, the tungsten filament in an ordinary light bulb.

Incident lightmeter An exposure meter that measures the amount of light incident to (falling on) a subject.
Incident light meter

Indoor film See Type A film, tungsten film.

Infinity The farthest position (marked -) on the distance scale of a lens. It includes all objects at the infinity distance (about 50 feet) from the lens or farther. When the infinity distance is within the depth of field, all objects at that distance or farther will be sharp.

Infrared The band of invisible rays just beyond red, which people perceive to some extent as heat. Some photographic materials are sensitive to infrared radiation.

Instant film A film such as Polaroid Time-Zero that contains the chemicals needed to instantly develop an image after exposure without the need for darkroom development.

Intensification A process increasing thedarkness of an already developed image. Used to improve negatives that have too little silver density to make a good print.

Interchangeable lens A lens that can beremoved from the camera and replaced with another lens, usually of a different focal length.
Interchangeable lenses

Inverse square law A law of physics stating that the intensity of illumination is inversely propor-tional to the square of the distance between light and subject. This means that if the distance between light and subject is doubled, the light reaching the subject will be only one quarter of the original.

ISO Film speed rating similar to ASA rating.
ISO rating of Agfa Agfapan APX 400

Latent image An image formed by the changes to the silver halide grains in photographic emulsion upon exposure to light. The image is not visible until chemical development takes place.

Leaf shutter A camera mechanism that admits light to expose film by opening and shutting a circle of overlapping metal leaves.

Lens A piece or several pieces of optical glass shaped to focus an image of a subject.

Lens shade A shield that fits around a lens to prevent unwanted light from hitting the front of the lens and causing flare. Also called a lens hood.

Light meter See exposure meter.

Light tight Absolutely dark. Protected by opaque material, overlapping panels, or some other system through which light cannot pass.

Line print An image resembling a pen-and-ink drawing, with black lines on a white background (or white lines on a black background). It is made with high-contrast lith film. Also called tone line print.

Lith film A type of film made primarily for use in graphic arts and printing. It produces an image with very high contrast.

Long lens A lens whose focal length is longer than the diagonal measurement of the film with which it is used. The angle of view with such a lens / film size combination is narrower at a given distance than the angle that the human eye sees.
Long lens

Luminance The light reflected or produced by a given area of a subject in a specific direction. Measurable by a reflected-light (luminance) meter.

Luminance meter See reflected light meter

Macro lens A lens designed for taking close-up pictures.

Macro photograph See photomacrograph.

Main light The principal source of light in a pho-tograph, particularly in a studio setup, casting the dominant shadows and defining the texture and volume of the subject. Also referred to as a key light.

Manual exposure A non-automatic mode of cam-era operation in which the photographer sets both the shutter speed and the aperture.

Manual flash A non-automatic mode of flash operation in which the photographer controls the exposure by adjusting the size of the camera aperture.

Mat A cardboard rectangle with an opening cut in it that is placed over a print to frame it. Also called an overmat.

Mat knife A short knife blade (usually replace-able) set in a large, easy-to-hold handle. Used for cutting cardboard mounts for prints.

Matte Describes a printing paper with a relatively dull, non-reflective surface. Opposite: glossy.

Middle gray A standard average gray tone of l8 percent reflectance. See gray card.

Mid tone An area of medium brightness, neither a very dark shadow nor a very bright highlight. A medium gray tone in a print.

Modeling light A small tungsten light built into some flash units. It helps the photographer judge the effect of various light positions because the duration of flash light is too brief to be judged directly.

Mottle A mealy gray area of uneven development in a print or negative. Caused by too little agitation or too short a time in the developer.

Pan 1) To follow the motion of a moving object with the camera. This will cause the object to look sharp and the background to blur. 2) See panchromatic film.

Panchromatic Film that is sensitive to all (or almost all) wavelengths of the visible spectrum, Abbreviated PAN.

PC connector See synch cord.

PC terminal The socket on a camera or flash unit into which a PC connector (synch cord) is inserted.

Perspective The apparent size and depth of objects within an image.

Photoflood An incandescent lamp that produces a very bright light but has a relatively short life.

Photogram An image formed by placing material directly onto a sheet of sensitized film or printing paper and then exposing the sheet to light.

Photomacrograph A close-up photograph that is life size or larger. Also called macrophotograph.
Macro photo

Photomicrograph A photograph that is taken through a compound microscope.

Photomontage A composite image made by cut-ting out and assembling parts of several photo-graphs.

Pincushion distortion A lens aberration or defect that causes straight lines to bow inward toward the center of the image.

Pixel Short for picture element, the basic unit of computer-usable information in digital image processing.

Plane of critical focus The part of a scene that is most sharply focused.

Platinum print A print in which the final image is formed in platinum rather than silver.

Polarizing filter A filter that reduces reflections from nonmetallic surfaces such as glass or water by blocking light waves that are vibrating at selected angles to the filter.

Positive Any image with tones corresponding to those of the subject. Opposite: negative.

Posterization An image with a flat, poster like quality. High-contrast lith film is used to sepa-rate the continuous gray tones of a negative into a few distinct shades of gray.

Primary colors Basic colors from which all other colors can be mixed. See subtractive, additive.

Print 1) A photographic image, usually a positive one on paper. 2) To produce such an image from a negative by contact or projection printing.

Printing frame A holder designed to keep sensi-tized material, usually paper, in full contact with a negative during contact printing.

Programmed automatic A mode of automatic exposure in which the camera sets both the shutter speed and the aperture that will produce the correct exposure.

Projection printing The process of projecting an image of a negative onto sensitized material usually paper. The image may be projected to any size, usually larger than the negative.

Projector An optical instrument for forming the enlarged image of a transparency or a motion picture on a screen.

Proof A test print made for the purpose of evaluating density, contrast, color balance, subject composition.

Push To expose film at a higher film speed rating than normal, then to compensate in part for the resulting underexposure by giving greater development than normal. This permits shooting at a dimmer light level, a faster shutter speed, or a smaller aperture than would otherwise be possible.

Rangefinder 1) A device on a camera that measures the distance from camera to subject and shows when the subject is in focus. 2) A camera equipped with a rangefinder focusing device. Abbreviated RF.

Raster streak A dark streak in photographs of a television screen or computer monitor images, caused by using too fast a shutter speed.

RC paper See resin-coated paper.

Reciprocity law The theoretical relationship between length of exposure and intensity of light, stating that an increase in one will be bal-anced by a decrease in the other. For example, doubling the light intensity should be balanced exactly by halving the exposure time. In fact, the law does not hold true for very long or very short exposures. This reciprocity failure or reciprocity effect causes underexposure unless the expo-sure is increased. It also causes color shifts in color materials.

Reducing agent The active ingredient in a devel-oper. It changes exposed silver halide crystals into dark metallic silver. Also called the develop-ing agent.

Reduction 1)A print that is smaller than the size of the negative. 2) The part of development in which exposed silver halide crystals forming an invisible latent image are converted to visible metallic silver. 3) A process that decreases the amount of dark silver in a developed image. Negatives are usually reduced to decrease density. Prints are reduced locally (only in certain parts) to brighten highlights. Opposite: intensification.

Reel A metal or plastic reel with spiral grooves into which roll film is loaded for development

Reflected light meter An exposure meter that measures the amount of light reflected or emitted by a subject. Sometimes called a luminance meter.

Reflector 1) A reflective surface, such as a piece of white cardboard, that can be positioned to redirect light, especially into shadow areas. Also called a flat. 2) A reflective surface, often bowl shaped, that is placed behind a lamp to direct more light from the lamp toward the subject.

Reflex camera A camera with a built-in mirror that reflects the scene being photographed onto a ground-glass viewing screen. See single-lens reflex, twin-lens reflex.
Relative aperture See aperture.

Replenisher A substance added to some types of developers after use to replace exhausted chem-icals so that the developer can be used again.

Resin-coated paper Printing paper with a water -resistant coating that absorbs less moisture than uncoated paper, consequently reducing some processing times. Abbreviated RC.

Reticulation A crinkling of the gelatin emulsion on film that can be caused by extreme tempera-ture changes during processing.

Reversal A process for making a positive image directly from film exposed in the camera; also for making a negative image directly from a neg-ative or a positive image from a positive trans-parency.

Reversal film Film that produces a positive image (a transparency) on exposure and development.

RF See rangefinder.

Rollfilm Film that comes in a roll, protected from light by a length of paper wound around the film.

Sabattier effect A partial reversal of tones that occurs when film or paper is re-exposed to light during development. Commonly called solariza-tion.

Safelight A light used in the darkroom during printing to provide general illumination without giving unwanted exposure.

Selective-contrast paper See variable-contrast paper.

Sharp Describes an image or part of an image that shows crisp, precise texture and detail.

Sheet film Film that is cut into individual flat pieces. Also called cut film.

Short lens A lens whose focal length is shorter than the diagonal measurement of the film with which it is used. The angle of view with this lens/ film combination is greater at a given distance than the angle seen by the human eye. Also called a wide-angle or wide-field lens.
Short Lens

Short lighting A portrait lighting set up in which the main source of light illuminates the side of the face partially turned away from the camera. Also called narrow lighting.

Shutter A mechanism that opens and closes to admit light into a camera for a measured length of time.

Shutter-priority A mode of automatic exposure in which the photographer selects the shutter speed and the camera sets the aperture that will produce the correct exposure.

Silhouette A scene or photograph in which the background is much more brightly lit than the subject.

Silver halide The light-sensitive part of common photographic emulsions; the compounds silver chloride, silver bromide, and silver iodide.

Single-lens reflex A camera in which the image formed by the taking lens is reflected by a mirror onto a ground-glass screen for viewing. The mir-ror swings out of the way just before exposure to let the image reach the film. Abbreviated SLR.

Slave An electronic flash unit that fires when it detects a burst of light from another flash unit.

Slave eye A sensor that detects light to trigger a slave flash unit.

Slide 1) A transparency (often a positive image in color) mounted between glass or in a frame of cardboard or other material so that it may be inserted into a projector. 2) A protective cover that is removed from a sheet film holder when film in the holder is to be exposed. Also called dark slide.

Slow Describes l) a film or paper that is not very sensitive to light; 2) a lens whose widest aper-ture is relatively small; 3) a long shutter speed.

SLR See single-lens reflex.

Sodium thiosulfate The active ingredient in most fixers.

Soft 1) Describes an image that is blurred or out of focus. 2) Describes a scene,
negative, or print of low contrast. 3) Describes a printing paper emulsion of low contrast, such as grade 0 or 1.

Solarization A reversal of image tones that occurs when film is massively overexposed. See Sabattier effect.

Speed I) The relative sensitivity to light of film or paper. 2) The relative ability of a lens to admit more light by opening to a wider aperture.

Spherical aberration A lens defect that causes rays that strike at the edges of the lens to be bent more than rays that strike at the center of the lens.

Spot To remove small imperfections in a print caused by dust specks, small scratches, or the like. Specifically, to paint a dye over small white blemishes.

Spotlight An electric light that contains a small, bright lamp, a reflector, and often a lens to con-centrate the light. Designed to produce a narrow beam of bright light.

Spot meter A reflected-light exposure meter with a very small angle of view, used to measure the brightness of a small portion of a subject.

Stereograph A pair of photographs taken side by side and seen separately by each eye in viewing them through a stereoscope. The resulting image looks three-dimensional.

Stock solution A concentrated chemical solution that is diluted before use.

Stop 1) An aperture setting on a lens.2) A change in exposure by a factor of two. One stop more exposure doubles the light reaching film or paper. One stop less halves the exposure. Either the aperture or the exposure time can be changed. 3) See stop down.

Stop bath An acid solution used between the developer and the fixer to stop the action of the developer and to preserve the effectiveness of the fixer. Generally a dilute solution of acetic acid; plain water is sometimes used as a stop bath for film development.

Stop down To decrease the size of a lens aperture.

Strobe 1) Abbreviation of stroboscopic. Describes a light source that provides a series of brief pulses of light in rapid succession. 2) Used loosely to refer to any electronic flash.

Subtractive color A way to produce colors by mixing dyes that contain varying proportions of the three subtractive primary colors-cyan, magenta, and yellow. Each dye subtracts its color from white light, leaving a balance of col-ored light. Dyes that absorb all wavelengths of light produce black.

Supplementary lens A lens that can be added to a camera lens for close-up work. It magnifies the image and permits focusing closer than normal to an object.

Synch cord An electrical cord connecting a flash unit with a camera so that the two can be syn-chronized. Pronounced "sink." See synchro-nize.

Synchronize To cause a flash unit to fire at the same time as the camera shutter is open.

Synchro sun A way to use flash lighting as fill light in a photograph made in direct sunlight. The flash lightens the shadows, decreasing the contrast in the scene. Also known as daylight flash.

T See time.

Tacking iron A small electrically heated tool used to melt the adhesive in dry-mount tissue, attach-ing it partially to the back of the print and to the mounting surface. This keeps the print in place during the mounting procedure.

Taking lens The lens on a camera through which light passes to expose the film.

Tank A container for developer or other processing chemicals into which film is placed for devel-opment.

Telephoto effect A change in perspective caused by using a long focal length lens very far from all parts of a scene. Objects appear closer together than they really are.

Telephoto lens Loosely, any lens of very long focal length. Specifically, one constructed so that its effective focal length is longer than its actual size. See long lens.

Tenting A way to light a highly reflective object. The object is surrounded with large sheets of paper or translucent material lighted so that the object reflects them and not the lamps, camera, and other items in the studio.

Thin negative Describes a negative or an area of a negative where relatively little silver has been deposited. A thin negative transmits a large amount of light.

Time A shutter setting marked T at which the shutter remains open until re-closed by the pho-tographer.

TLR See twin-lens reflex.

Tone 1) To change the color of a print by immers-ing it in a chemical solution. 2) The lightness or darkness of a particular area. A highlight is a light tone; a shadow is a dark tone.

Transparency An image on a transparent base, such as film or glass, that is viewed by transmit-ted light. See slide (1).

Tripod A three-legged support for a camera. Usu-ally the height is adjustable and the top or head is movable.

Tungsten film Color film balanced to produce accurate color renditions when the light source that illuminates the scene has a color tempera-ture of about 3200K, as do many tungsten lamps. Sometimes called Type B film. See Type A film.

Tungsten light Light such as that from an ordi-nary light bulb containing a thin tungsten wire that becomes incandescent (emits light) when an electric current is passed along it. Also called incandescent light.

Tv Abbreviation of time value. Used on some camera information displays as a shortened way to refer to shutter speed settings.

Twin-lens reflex A camera in which two lenses are mounted above one another. The bottom (taking) lens forms an image on the exposed film. The top (viewing) lens forms an image that reflects upward onto a ground-glass viewing screen. Abbreviated TLR.

Type A film Color film balanced to produce accurate color renditions when the light source that illuminates the scene has a color temperature of about 3400K, as does a photoflood. See tungsten film.

Type 8 film See tungsten film.