•Quantum - smallest indivisible unit of radiant energy.
•Quarterplate - negative or print format measuring 3 ¼ x 4 ¼ inches. It's one quarter the size of a full plate (8 ½ x 6 ½ inches).
•Quartz-iodine lamp - compact tungsten filament lamp designed to maintain its color temperature and light intensity throughout its working life.
•Rack and pinion focusing - mechanical focusing system used on copying or monorail cameras. A pinion engages a rack on a slide. Focusing is achieved by turning a knob or wheel, which moves the lens or image panel.
•Radiography - technique of using X-rays, gamma rays and charged particles to form shadow images on photographic materials. Used in medical and industrial research because of its ability to penetrate opaque objects.
•Rapid fixer - fixing solution that uses ammonium thiocyanate or thiosulfate instead of hypo.
•Rapid rectilinear - lens system composed of two matching doublet lenses, symmetrically placed around the focal aperture. It was introduced by Dallmeyer and Sternheil and removed many of the aberrations present in more simple constructions.
•Rayographs - term coined by Man Ray and his friends for pictures made by placing directly on photographic paper (i.e. photograms).
•Rear curtain sync - when the flash fires an instant before the second or rear curtain of the focal plane shutter begins to move. When slow shutter speeds are used, this feature can create a blur effect from the ambient light, i.e., patterns following a moving subject with subject movement frozen at the end.
•Rear focus - refers to the focused area behind the picture's subject.
•Rear focusing system - system where only the rear lens group moves during focusing. It eliminates changes in the physical length of the lens during focusing.
•Rebate - margin on photographic film surrounding the image area.
•Reciprocity failure - in photographic emulsions occurs when exposure times fall outside a films normal range. At these times an increase in exposure is required in addition to the assessed amount. This can be achieved either by increasing intensity or time.
•Reciprocity law - states that exposure = intensity x time, where intensity is equal to the amount of light and time is equal to the time that amount of light is allowed to act upon the photographic emulsion.
•Reconstituted image - photograph produced by translating light from the subject into electronic signals.
•Recycling time - time it takes a flash unit to recharge between firings.
•Red eye - effect encountered when light from a flash unit travels parallel to the lens axis during exposure.
•Reducers - solutions which remove silver from negatives and prints. They are used to diminish density and alter contrast on a photographic emulsion.
•Reducing agent - chemical in a developing solution which converts exposed silver halides to black metallic silver.
•Reflected light - light bounced off a subject, not falling on it.
•Reflected light reading - measurement by a light meter of the amount of reflected light being bounced of the subject. The light meter is pointed towards the subject.
•Reflecting telescope - telescope using a concave parabolic mirror to increase focal length and focus light at a point.
•Reflections - rays of light which strike a surface and bounce back again. Specular reflection occurs on even, polished surfaces; diffuse reflection occurs on uneven surfaces, when light scatters.
•Reflector - any substance from which light can be reflected. It also describes a white or gray card used to reflect from a main light source into shadow areas.
•Reflex camera - camera system which uses a mirror to reflect incoming image rays on to a ground glass screen, providing a system of viewing and focusing. See also SLR.
•Reflex lens - alternative term for mirror lens.
•Refraction - change in direction of light rays as they pass obliquely from one transparent medium to another of different density, e.g. air to glass.
•Refractive index - numerical value indicating the light bending power of a medium such as glass. The greater the bending power, the greater the refractive index.
•Register punch - punched used to make alignment holes in film or paper for registering images.
•Rehalogenization - process by which black metallic silver is converted back to silver halides. It is used in bleaching for toners and intensification.
•Relative aperture - measurable diameter of the diaphragm divided by the focal length of the lens in use and expressed in terms of "f" numbers, marked on the lens barrel.
•Replenishment - addition of chemicals to a processing solution to maintain its characteristics, e.g. developers are replenished with reducing agents as the old ones are exhausted through use.
•Resin coated paper (RC) - printing paper with a water repellent base. RC Paper can be processed faster, require less washing, and dry more quickly than fiber based papers.
•Resist - protective but removable layer applied to a surface in the form of a pattern or image. Used to prevent chemicals solutions reaching covered areas.
•Resolving power - ability of the eye, lens or photographic emulsion to determine fine detail. In photography, the quality of the final image is a result of the resolving power of both the lens and the sensitive emulsion. Resolution is expressed in terms of lines per millimeter which are distinctly recorded or visually separable in the final image.
•Restrainer - chemical constituent of developing solutions which helps prevent reducing agents from affecting unexposed halides and converting them to black metallic silver.
•Reticulation - regular crazed pattern created on the emulsion surface of negatives which is caused by extreme changes of temperature or acidity/alkalinity during processing.
•Retrofocus - type of lens design with a negative lens element positioned in front of the diaphragm and a positive lens element positioned at the rear of the diaphragm. This makes the distance from the rear of the lens to the focal plane longer than the lens focal length. Retrofocus design has been adopted in wide angle lenses so the rear of the lens does not impede the movement of an SLR camera's reflex mirror.
•Retouching - after treatment carried out on a negative or print, in the form of local chemical reduction, local dye or pencil additions or air-brushing. The purpose is to remove blemishes on the negative or print.
•Reversal materials - materials specifically designed to be processed to a positive after one camera exposure.
•Ring flash - ring shaped electronic flash unit attached to the front of a lens. Used to give even frontal lighting in closeup situations.
•Rinse - brief clean water wash between steps of a processing cycle to reduce carry-over of one solution into another.
•Rising front - camera movement enabling the front lens panel to be raised or lowered from its central position on most view cameras.
•Rods - receptors forming part of the retina at the back of the eye sensitive only to variations in brightness, not color.
•Roll film - refers to 120, 220 and 620 film formats.
•Roll film adaptor - specially designed attachment for cameras designed for cut film, enabling roll film to be used.
•Sabattier effect - part positive part negative effect formed when an emulsion is briefly re-exposed to white light during development, and then allowed to continue development. Also known as pseudo-solarization.
•Safelight - darkroom light of a color and intensity that will not affect light sensitized photographic materials.
•Safety film - term used to describe a film with a base that is not readily inflammable.
•Sal-ammoniac - ammonium chloride. used in some high speed developers.
•Sandwiching - combination of two or more negatives or film positives in the negative carrier or masking frame when printing or enlarging.
•Saturated color - pure color hue, undiluted by other colors, white or gray, i.e. the primary colors, red, yellow and blue are saturated colors.
•Scale - linear relation between the size of the subject and the size of its image.
•Scanning electron microscope - device used in photomicrography.
•Schumann plate - plate coated with an emulsion with so little gelatin content that the silver halide grains protrude above its surface. Used for photography in the ultraviolet region.
•Screening - conversion of a continuous tone image to a half-tone image.
•Screen plate - plate used in early additive forms of color photography.
•Scrim - lighting attachment which, when placed in front of a lamp, reduces its strength, usually by one stop, without affecting lighting quality or color.
•Selective focusing - method of adjusting the lens aperture and shutter speed to give a depth of field that will limit image sharpness to a particular area of the image.
•Selenium - light-sensitive substance which, when used in a barrier-layer construction, generates electrical current when exposed to light. Used in exposure meters.
•Selenium cell - light sensitive cell used in many types of exposure meters. It generates electricity in direct proportion to the amount of light falling upon its surface.
•Self-timer - mechanism for delaying the opening of the shutter for a given number of seconds after the release has been operated.
•Self toning paper - obsolete silver chloride paper used for contact printing in daylight.
•Sensitive material - in photography, refers to materials that react to the actinic power of light.
•Sensitivity - degree of response of a photographic emulsion to exposure to light.
•Sensitometry - scientific study of the response of photographic materials to exposure and development. It establishes emulsion speeds and recommended development and processing times.
•Separation images - technique of producing an image by combining photographs produced on a material or using equipment which is sensitive to one region of the visible spectrum.
•Separation negatives - black & white negatives, usually prepared in lots of three or four, which have been taken through filters which analyze the color composition of an original in terms of blue, green and red. They are used particularly in photomechanical color printing and dye transfer printing processes.
•Shading - see Local control.
•Shadow detail - details visible in areas that are darkest in the subject.
•Shadows - darkest areas in a photographic print.
•Sheet film - alternative term for cut film.
•Shelf life - length of time unused material or chemicals will remain fresh.
•Shellac - natural resin with a low melting point. It is mainly used on dry mounting tissue.
•Shutter - mechanical system used to control the time that light is allowed to act on the sensitive emulsion.
•Shutter priority camera - semi-automatic camera on which the photographer selects the shutter speed, and the camera automatically sets an appropriate aperture.
•Shutter speed - action of the shutter that controls the duration of an exposure. The faster the speed the shorter the exposure. Shutter speed settings are given in the fraction of a second. Each setting is half the duration of the preceding one in a constant scale, marked on the shutter speed dial or ring.
•Side lighting - light striking the subject from the side relative to the position of the camera. It produces shadows and highlights to create modeling on the subject.
•Silhouette - photographic image in which the subject is seen as a solid black shape against a light background.
•Silicon release paper - thin, heat resistant interleaving paper, used between a photographic print and textured material in a heated press. It allows remolding of the print surface yet prevents the two materials from sticking together.
•Silk print - image made on silk by means of the diazo or dye printing methods.
•Silkscreen - method of applying inks to paper or similar materials using a nylon stencil produced by photographic means.
•Silver dye bleach material - integral tripack printing material.
•Silver halides - light sensitive crystals used in photographic emulsions, i.e. silver bromide, silver chloride and silver iodide. The change from white to black metallic silver when exposed to light.
•Silver nitrate - chemical combination of silver and nitric acid. It is used in intensifiers, physical developers and photographic emulsions manufacture.
•Silver reclamation - system for recovering silver from exhausted solutions.
•Silver recovery - system of reclaiming silver from exhausted solutions.
•Silver salts - compounds of silver.
•Simultaneous contrast - effect that adjacent color hues have upon each other.
•Single lens reflex (SLR) - stands for single lens reflex. It is a camera of 35mm or medium format in which a system of mirrors shows the user the image precisely as the lens renders it.
•Single servo AF - when focus is locked as long as the shutter release button is lightly pressed.
•Sizing - very dilute, gluey substance used to prepare surfaces for coating by filling in pores and giving even absorbance.
•Sky filter - outdated term for a filter which has a graduated density across its surface.
•Sky shade - alternative term for a lens hood.
•Slave unit - mechanism which fires other flash sources simultaneously when a photo-electric cell is activated by the illumination emitted by a camera linked flash.
•Slide - alternative term for a projection transparency.
•Slit shutter - narrow vertical slit either just in front of the emulsion or at a similar distance in front of the lens. Film is wound through the camera at a constant speed giving one long image along the length of the film.
•Slow film - film having an emulsion with low sensitivity to light. Typically films having an ISO or 50 or less.
•Slow lens -lens with a small maximum aperture, such as f/8.
•Slow sync - flash technique for using the flash at a slow shutter speed. Flash shooting in dim light or at night at a fast shutter speed often results in a flash-illuminated subject against a dark background. Using a slower shutter speed with the flash brings out the background details in the picture.
•Slide - photographic transparency mounted for projection. It represents first generation production of an image.
•Snapshot - term once used to describe a photograph taken with the I (instantaneous) setting on cameras. The term originally came from rifle shooting, when little or no time is allowed for aiming.
•Snoot - cone shaped shield used on spotlights to direct a cone of light over a small area.
•Sodium bichromate - chemical used in intensifiers, toners and bleaches.
•Sodium bisulfite - chemical used in fixing baths as an acidifying agent.
•Sodium carbonate - alkaline accelerator used in many general purpose and print developers.
•Sodium chloride - used in some bleaches and reducers.
•Sodium hexametaphosphate - water softener.
•Sodium hydrosulfite - used as a fogging agent in reversal processing.
•Sodium hydroxide - highly active alkaline accelerator used in conjunction with hydroquinone to produce high contrast developers.
•Sodium metabisulfite - used as an acidifying agent in acid fixing baths.
•Sodium sulfide - chemical used in sulfide (sepia) toning.
•Sodium thiocyanate - alternative to potassium thiocyanate and is used as a silver solvent in physical and ultra-fine grain formulae.
•Sodium thiosulfate - chemical used in many fixing solutions. It converts unused halides to a soluble complex which can be removed by washing.
•Soft developer - paper developer that can be used alone or in combination with other developers (two-bath development) to achieve more subtle contrast control.
•Soft focus - definition of a diffused image. This can be achieved at the camera or enlarging stage.
•Soft focus lens - lens, uncorrected for spherical aberrations, used to produce a soft focus effect.
•Solarization - reversal or partial reversal of tones in a photographic image caused by vast amounts of over-exposure. It is often inaccurately used to describe the partial reversal effect caused by fogging photographic material with light, which is actually the Sabattier effect.
•Solubility - in general terms is the ease with which a solid will mix homogeneously with water to provide a chemical solution.
•Spacing bracket - device used to position the camera at the right distance from the subject for the lens focus setting in closeup work.
•Spectral sensitivity - relative response of a photographic emulsion to each of the colors of the spectrum, including infrared and ultraviolet.
•Spectrum - usually used in reference to the visible part of the electro-magnetic spectrum, i.e. the color bands produced by diffraction, and arranged according to wavelength, when white light is passed through a prism.
•Speed - sensitivity of a photographic emulsion to light. Films are given ISO or DIN numbers denoting speed characteristics.
•Spherical aberration - lens fault which causes loss of image definition at the image plane. Its affects are reduced by stopping down.
•Split image rangefinder - see Rangefinder.
•Spool - bobbin like object consisting of a narrow core with flat disks on either end, around which the film is wound.
•Spotlight - artificial light source using a fresnel lens, reflector, and simple focusing system to produce a strong beam of light of controllable width.
•Spot meter - used to get accurate light readings of a small part of a subject. It uses a narrow angle of view to measure within limited areas.
•Spotting - method of retouching. Blemishes or unwanted details are removed from negatives and prints by brush and dye or pencil.
•Sprocket holes - perforations on both edges of 35mm film, which engage with the teeth of the film transport mechanism.
•Squeegee - tool with rubber blades or rollers, used to squeeze water out of wet prints.
•Stabilization - alternative method of fixing. Unused halides are converted to near stable compounds, insensitive to light. No washing is required.
•Stabilizer - final solution often used in color processing which leaves the dyes produced by chemical development more stable and fade resistant.
•Staining developer - developer, such as pyro, in which the oxidation products give extra image density by staining the gelatin.
•Stand - alternative name for a tripod.
•Standard lens - lens with a focal length approximately equal to the diagonal of the film format with which it is used.
•Stand camera - large format camera usually mounted on a rigid stand.
•Static marks - jagged fog marks on negatives as a result of a very dry film being rewound or unwound too rapidly.
•Step wedge - printed series of density increases, in regular steps from transparent to opaque. Its a method of making exposure tests when enlarging.
•Stereoscope - viewer which accepts pairs of stereoscopic images.
•Stereoscopic camera - camera designed to take simultaneous images of the same subject from viewpoints separated by the same distance as that between the eyes.
•Stereoscopy - method of creating a three dimensional effect on a two dimensional surface using a pair of images taken from slightly different viewpoints, and viewed through specially made stereo viewers.
•Still life - inanimate subject, either in the studio, or outdoors, normally arranged to make full use of form, shape and lighting.
•Stock solution - processing chemicals which may be stored in a concentrated state and diluted just before use.
•Stop - aperture of a camera or enlarging lens.
•Stop bath - chemical bath whose purpose is to stop development by neutralizing unwanted developer. This increases precision of development and prevents carry over of one chemical into another during development.
•Stopping down - reducing the size of the lens aperture and thus the amount of light passing into the camera. It increases depth of field.
•Stop down metering - TTL metering in which the light is measured at the picture-taking aperture.
•Stop down metering - TTL metering in which the light is measured at the picture-taking aperture.
•Straight photography - term used to describe picture making with minimal manipulation of the photographic process.
•Stress marks - black lines on a photographic emulsion caused by friction or pressure.
•Strobe light - low power electronic flash that can fire repeatedly at regular, controlled intervals.
•Studio camera - term given to a large format 12 x 15 inch camera on a wheeled stand.
•Subbing - layer applied to a photographic support as a foundation for the emulsion.
•Subject - person or thing photographed.
•Subjective photography - interpretive image of the subject, with results influenced by the attitude of the photographer.
•Sub-miniature camera - camera using a film format smaller than 35mm.
•Substantive film - color film in which the color couplers are contained within the emulsion.
•Subtractive primaries - yellow, magenta and cyan.
•Subtractive synthesis - combination color system used in modern photography materials. The complimentary colors of yellow, magenta and cyan are formed to provide a reasonably full color image.
•Successive color contrast - trick of the human eye by which the impression of a color is influenced by an immediately preceding color stimulus.
•Sulfide toning - conversion of a black metallic silver image into a brown dye image. Usually known as sepia toning.
•Sulfuric acid - high corrosive chemical used in reducers.
•Supper coat - top coating of non-sensitized gelatin added to sensitized emulsions to form a protective layer.
•Supplementary lenses - additional lens elements used with the standard camera lens to provide a new focal length.
•Surface development - development process in which the image forms primarily on the surface of the emulsion and then penetrates deeper.
•Surge marks - streaks on the image from each of the sprockets holes of 35mm film caused by excessive agitation.
•Surrealism - originally an early 1920s artistic movement, now taken to indicate the production of unreal images which defy reason.
•Swing back/front - term used to describe the movable lens and back panels of most view and monorail cameras. They allow manipulation of perspective and depth of field.
•Symmetry - effect of an evenly balanced arrangement of visual information, such as pattern, on either side of a central division.
•Synchronized flash - method of synchronizing flash light duration with the maximum shutter opening.
•Synchro-sunlight - system of combining daylight and flash to achieve a controlled lighting ratio.
•T (Time) - shutter speed setting used for timed exposures longer than the numbered settings. The shutter opens when the release is pressed and closes when it is pressed again. Now largely super ceded by B (Bulb).
•Tacking iron - heated tool used to stick part of the dry-mounting tissue to a print and its mounting board.
•Tanks - containers for holding chemical solutions for processing films and plates.
•Tanning development - type of developer used for processes that require a relief image, such as dye transfer.
•Technical camera - see View Camera.
•Teleconverter - optical system mounted between a camera body and the lens to increase the effective focal length of the lens.
•Telephoto lens - compact lens construction which provides a long focal length with a short back focus.
•Tempering bath - large tank or deep tray filled with water maintained at the correct temperature for processing. Used to house tanks, drums or trays as well as containers of processing solutions.
•Tessar lens - famous German non-symmetrical lens design by Zeiss. It is based on the triplet lens.
•Test strip - trial and error method of calculating exposure in photographic printing. A number of exposures are given to a strip of emulsion, over important areas of the image to help judge the correct exposure in the final print.
•Texture - broadly defined as the surface character of an object.
•Texture screen - transparent film or glass printed with a fine background pattern. They're interposed between the image and the paper to break up large areas of tone or for special effects.
•T-Grain technology - name for Kodaks film emulsion technology used in all Kodak APS films. Uniquely shaped grains that align better than conventional silver crystals absorb and transmitting light more effectively to produce sharper images.
•Thermography - recording images by means of the heat radiated from the subject.
•"Thick" negative - antique term used to describe a dense negative.
•"Thin" negative - antique term used to describe a negative lacking in density.
•Through-the-lens - see TTL.
•Thyristor flash gun - automatic flash gun which cuts off the flash when the exposure is correct. This conserves power, makes recycling quicker, and battery life longer.
•Time and temperature - controlling factors of a chemical photographic process.
•Time exposure - general term for an exposure longer than can be set using the camera's fixed shutter speeds.
•Time gamma curve - see Gamma.
•Time lapse photography - method of recording chemical and physical changes in a subject over a period of time by photographing it at regular intervals from the same viewpoint.
•Timer - clock used to control processing.
•Tinting - application of color tints, usually in the form of dyes or paints, to a photographic image to create or enhance color.
•Tin-type - see Ferrotype.
•Tomography - radiographic technique used in medial photography.
•Tone - refers to the strength of grays between white and black. It relates to the brightness, lightness and darkness of the subject and is determined by illumination.
•Tone line process - technique used to reproduce a photographic image so that it resembles a pen and ink drawing.
•Toners - used to change the color of the photographic print by chemical baths. Through the system of bleaching and toning, the black metallic silver image is converted to a dye image.
•Tone separation - process of reducing the tonal range of a photograph to a very restricted range. The final result has strong highlights and deep shadows with a set number of intermediate tones. Also refereed to as Posterization.
•Tone values - various shades of gray between the extremes of black & white in a photographic image.
•Toning - method of soaking the print in selenium or similar chemical(s) to help give the print an overall feeling of "richness".
•Transfer processes - methods of transferring a photographic image from one surface to another.
•Transmission - passage of light through a transparent or translucent material.
•Transmitted light - light which is passed through a transparent or translucent medium. The amount of light transmitted depends on the density of the medium through which it is passed and on the brightness of incident light source. Transmitted light is always less than incident light, but the amount of loss depends on the density of the medium.
•Transparent magnetic layer - information storage layer built into Advanced Photo System film that enables enhanced information exchange capabilities.
•Transposing frame - frame used for printing pairs of stereoscopic negatives from a two lens camera.
•Tray development - any process carried out in open trays rather than using tanks or similar apparatus.
•Trichrome Carbro Process - method of making assembly color prints from separation negatives, using an adaption of the carbro process.
•Tri-color filters - filters in deep primarily colors used to expose color prints by the additive method.
•Trigger - term used to describe a shutter release.
•Tripack - photographic material, used in color photography, consisting of three emulsion layers of different sensitivity each on its own base. It is used to obtain three separation negatives with a single exposure.
•Triple extension - camera system in which lens-image distance can be extended by as much as three times its focal length. It is particularly useful for close-up photography.
•Triplet lens - lens consisting basically of three elements, a diverging lens sandwiched between two converging lenses.
•Tripod - three legged camera support. The legs usually feature sections that permit height adjustments.
•T setting - see T (Time).
•T stops - more accurate measurement of light entering a lens than "f" numbers. Whereas "f" numbers represent the ratio between measured diameter and focal length, "t" stops are based on actual light transmission at different diameters.
•TTL - abbreviation for "through-the-lens" as referring to a metering system in which a suitable light sensitive mechanism within the camera body measures exposure from the image light passing through the lens.
•Tungsten filament - artificial light source using a tungsten filament contained within a glass envelope.
•Tungsten halogen lamp - improved version of the normal tungsten lamp. It is much smaller and more consistent in color temperature as the glass envelope used is non-blackening.
•Tungsten light - light from standard room lamps and ceiling fixtures, not fluorescent.
•Tungsten light film - See Type B Film.
•Twin lens reflex (TLR) - camera having two lenses of the same focal length. One is used for viewing and focusing, the other for exposing the film.
•Two-bath development - development of negatives in two stages. Developer without alkali is followed by an alkali bath, which activates development.
•Two-color photography - simple method of color photography which analyzes the spectrum into two parts instead of three, forming images which are combined with complementary colors.
•Type A film - color film balanced to artificial light sources at a color temperature of 3400K.
•Type D film - obsolete term for film balanced for daylight.
•Ultrasonic image recording - image formation by measurement of ultrasound echoes translated electronically into a scanned visual image on a TV display. Also known as sonography.
•Ultraviolet (UV) - part of the electromagnetic spectrum from about 400nm down to 1nm. It is invisible to the human eye, but most photographic materials are sensitive to near UV bands down to 250nm. It records as increased haze, particularly in distant views and at high altitudes, and may give a blue cast in color images. technique of projecting an infrared image on a phosphorescent surface.
•Under-development - reduction in the degree of development. It is usually caused by shortened development time or a decrease in the temperature of the solution. It results in a loss of density and a reduction in image contrast.
•Underexposure - result of too little exposure in the camera or at the enlargement stage.
•Universal developer - name given to a number of developing solutions, usually MQ, indicating that they can be used for processing films and papers.
•Uprating - no longer used term to define the process of increasing the manufacturers film speed by the use of: hypersensitizing; using specially prepared proprietary developers; or by a two stage process.
•Uranium Nitrate - chemical used in toners and developers.
•UV filter - filter which is used to absorb ultraviolet (UV) radiation.
Photography Glossary - V
•Vacuum back is a camera back with a perforated plate through which air is drawn by a pump. A sheet of film is therefore sucked flat against the plate and held firmly during exposure. Used for special large format cameras such as copying devices where dimensional accuracy is critical.
•Vacuum easel is a compact printing frame which ensures firm contact between the film and paper by excluding air between the surfaces. Some types are used to hold the paper flat on the enlarger baseboard when enlarging.
•Vanishing point is the point at which parallel lines, viewed obliquely, appear to converge in the distance.
•Vapor discharge lamp is a lamp in which electrical current passes through a vapor or gas rather than through a wire filament, thus producing illumination.
•Variable contrast paper is a printing paper in which the contrast can be varied depending on the color of the printing light. This can be altered by using different color filters.
•Variable focus lens is a lens whose focal length can be continually varied within a given range. Also known as a zoom lens.
•Veil is a uniformly distributed silver deposit in a photographic image, not forming part of the image itself. Also known as fog.
•Video still camera is a camera using an electronic charge coupled device instead of film.
•View camera is a large format camera which has a ground glass screen at the image plane for viewing and focusing.
•Viewfinder is a system used for composing and sometimes focusing the subject. There are several types: direct vision, optical, ground glass or reflex.
•Viewpoint is the position of the camera in relation to the subject.
•Vignetting is a printing technique where the edges of the picture are gradually faded out to black or white. It also refers to a fall off in illumination at the edge of an image, such as may be caused by a lens hood or similar attachment partially blocking the field of view of the lens.
•Vinyl film is an emulsion coating on a polyvinyl chloride acetate base, with less shrinkage than conventional film bases.
•Viscose sponge is a synthetic sponge used to wipe surplus water off films before they are hung up to dry.
•Viscous processing is a process using chemicals carried in sticky semifluid substances instead of normal liquids. Used for instant picture processing.
•Volt is a unit of electrical potential difference and electromotive force.
•Voltage stabilizer is a transformer used to produce a steady output voltage despite fluctuations of input voltage.
•Vortograph is an abstract photograph made with a simple kaleidoscopic apparatus, first used by Alvin Langdon Coburn in 1917.
•Warm colors are any colors which, by association, suggest warmth, such as red, orange and yellow.
•Warm tone developer is a developer producing image colors in chlorobromide papers ranging from warm black to reddish brown, according to type.
•Washing is the final part of the processing cycle, which removes residual chemicals and soluble silver complexes from the emulsion.
•Water bath are large water filled containers used to maintain processing trays, tanks or chemicals at the correct temperature.
•Waterproof paper is another term for Resin-coated paper.
•Water softeners are used to eliminate most of the minerals and slats found in hard water.
•Watkins factor is an old system of development control, based on observation of the processing image under safe lights.
•Watt is a unit of power in electricity.
•Watt-second is an alternative unit of energy, equal to the joule.
•Wavelength describes the distance from wave-crest to wave-crest between two corresponding waves of light in the electro-magnetic spectrum. Wavelengths are measured in nanometers (nm) and Angstrom units (A).
•Waxed paper process is an early form of photography. A variation on the calotype process.
•Weak is a negative or print which is low in contrast or density.
•Wedge spectrogram is an indication of the spectral sensitivity of a sensitized material by exposing it to a spectrum of light through a graduated gray wedge.
•Wet collodion is a much improved calotype developed by Frederick Scott Archer. A sensitized glass plate was dipped into a bath of silver nitrate and exposed while still wet. The improved speed made much shorter exposures possible.
•Wet processing is processing by the application of chemicals in fluid form. The traditional method of photographic processing.
•Wetting agents are chemicals which, when used in minute quantities, reduce the surface tension of water. They are usually added to the final wash of films and plates to improve draining.
•White Light see White Light Spectrum.
•White light control is the level or switch on a color enlarger which removes all color filtration and returns it when required.
•White light spectrum is the electromagnetic wavelengths between 400-700 nanometers. Also referred to as the visible spectrum.
•Whole plate is a negative or print format measuring 6 ½ x 8 ½ inches.
•Wide-angle lens is a lens with wide covering power. It has a focal length which is less than the diagonal of the film format with which it is being used.
•Wide-angle rack is an additional focusing rack used on large format cameras.
•Wide area AF means the autofocus detection area is wider than normal. Making it easier to photograph moving subjects.
•Wood print is a print made on a wood surface which has been photochemically prepared.
•Working aperture is the widest aperture at which an acceptable image can be achieved.
•Working solution is a liquid chemical that has been mixed and diluted for use.
•Xenon is a rare gas sometimes used with electronic flash tubes and enclosed arc light sources.
•Xerography is a photographic process which uses an electrically charged metal plate. On exposure to light the electrical charge is destroyed, leaving a latent image in which shadows are represented by charged areas. A powdered pigment dusted over the plate is attracted to the charged areas, producing a visible image.
•Xography is a system of photography which produces prints and transparencies with a three-dimensional effect. A cylindrically embossed lenticular screen is placed in contact with the film and a shutter behind the lens is arranged to scan the subject during exposure.
•X ray are electromagnetic radiations beyond ultraviolet which, when passed through a solid object and allowed to act upon a sensitive emulsion, form a shadow image of the internal structure of the object.
•X ray film is spectral sheet film for radiography, having a thick emulsion coated on both sides of the support to increase the absorption of X rays.
•X setting (X sync) is the setting that causes the flash to burst in synchronization with the shutter. For some manual cameras, the X synch speed refers to the maximum speed that the camera can synchronize with the flash.
Photography Glossary - Y
•Yellow is the color formed by mixing red and green light. Yellow is complimentary to blue, and is one of the three colors used in subtractive color synthesis.
•Zirconium lamp is an arc lamp used in powerful enlarges and projectors.
•Zoetrope is an early device for creating illusion of continuous motion. A sequence of still pictures was viewed so quickly through slits in a rotating drum, that the images appeared to merge.
•Zone focusing is a method of focusing the lens so that the depth of field extends over a preselected range of distances.
•Zone system is the method of determining exposure and development required for individual scenes, invented by Ansel Adams. It is based on analysis of subject luminosities in terms of ten gray tones, labeled zones 0 through X and previsualizing them as print densities. By measuring each subject luminance with a hand meter it is possible to determine how much the range of values must be contracted or expanded by negative development control to give the required values in the print.
•Zoom lens is a lens which is constructed to allow continuously variable focal length within a specific range. The effective aperture and focus settings remain unchanged throughout such adjustments
