This glossary contains alphabetical listing of Black and White Darkroom related terms & their definitions.

Agitation ::. Keeping the developer, stop bath, or fixer in a gentle, uniform motion while processing film or paper. Agitation helps to speed and achieve even development and prevent spotting or staining.

Archival Processing ::. Extra steps are taken when developing and printing to ensure the most stable image is made.

Bitumen ::. Hydro-carbon which hardens by the action of light. It was used by Joseph Nicephore Niepce to produce the world’s first photograph in the early 19th century.

Base Exposure Time ::. The initial exposure time used for making a “straight” print. This is determined by using a test strip.

Bleaching ::. Lightening selected areas of the image using bleaches or reducers. The most common bleach is potassium ferricyanide. Other tonal techniques include burning, dodging, flashing, and toning.

Burning ::. Allowing more light to fall upon a particular area of the print making that area darker. Other tonal techniques include dodging, flashing, toning, and bleaching.

Black & White ::. A photographic film or paper used to create monochrome images. Though we think of black and white mainly in terms of a gray scale, prints can have a wide variety of subtle tones, from blue- to brown-black. Though the overwhelming majority of photography today is shot and printed in color, black-and-white has attracted a fiercely loyal and dedicated group of photographers.

Burn-out ::. Jargon that refers to loss of details in the highlight portion of a scene due to overexposure. With slide film, it might mean that no image detail has been recorded on the film, or that highlights show no texture or tonal information. A highly burnt-out or burnt-up slide may show clear film base in overexposed areas.

Characteristic Curve Regions ::. The characteristics curves are shaped similar to a ski ramp, with the bottom portion sloping up slightly (called the “toe”), a steep middle portion known as the “straight line” and a top portion that begins to flatten out (called the “shoulder”). Both film and paper characteristic curves are similar in shape.

Color Enlarger Head ::. A type of head of an enlarger that has a set of three color filters (cyan/magenta/yellow) that can be adjusted to make a color print from a negative or transparency. It can also be used to produce different paper grades using special variable contrast paper.

Cold Light Enlarger ::. A diffusion type of enlarger with fluorescent lamps as the light source. These types of enlarger heads scatter the light more evenly across the surface of the negative. One advantage of the cold light head is that it can render more subtle tonal gradations and will minimize the effect of dust and scratches on the negative which are translated to the print. The cold light head does generate some heat while in operation, but considerably less than its condenser enlarger counterpart.

Chlorobromide Paper ::. Photographic paper coated with an emulsion made up of both silver chloride and silver bromide. Used for producing enlargements with a warm, slightly brownish-black image, especially if processed in a Warm Tone Developer.

Contrast, Contrast Values ::. The perceived difference between light areas (highlights) and dark areas (shadows) of a scene. The range of contrast levels between the highlights and the shadows is called Contrast Values.

C-41 ::. The current process for all standard color negative films.

Contact Print ::. A print made by exposing photographic paper while it is held tightly against the negative with a clear glass on top to weight it down. Images in the print will be the same size as those in the negative.

Contrast Grade ::. Numbers (usually 1-5) and names (soft, medium, hard, extra-hard, and ultra-hard) of the contrast grades of photographic papers, to enable you to get good prints from negatives of different contrasts. Use a low-numbered or soft contrast paper with a high contrast negative to get a print that most closely resembles the original scene. Use a high-numbered or an extra-hard paper with a low-contrast negative to get a normal contrast paper.

Condenser Enlarger ::. An enlarger with a sharp, undiffused light that produces high contrast and high definition in a print. Scratches and blemishes in the negative are emphasized.

Dye Transfer Print ::. Introduced in 1946, Dye Transfer is the finest color printing process in the history of photography. The colorants produce an amazingly wide spectrum of colors, defining the largest color space of any process in existence. The extremely long tonal scale of Dye Transfer retains detail in both bright highlights and dense shadows. Dye Transfer is the only continuous-tone color process yielding prints on a fiber-base. Prints may be displayed for many decades without fading, and have a dark storage stability of over 500 years.
 
Density, Image Density ::. Buildup of silver deposits in a particular area produced by exposure and development. The more silver present in a shadow, the more the image density. Conversely, the less silver deposit in the highlights, the less the image density. Technically, density is measured in terms of the logarithm of opacity.

Drying marks ::. If water drops form on the surface of drying film they will leave a residual mark as they dry.

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.

Developer ::. Chemical solution used to convert the invisible silver halide crystals in the film emulsion into visible metallic silver.

Dilution ::. Reduction in the strength of a liquid by mixing it with an appropriate quantity of water.

Dodging ::. Holding back light from a particular area of the print to make that area lighter. Other tonal techniques include burning flashing, toning, and bleaching.

D-76 [KODAK] ::. Equivalent to Ilford ID-11 powder developer/replenisher. Virtually identical formula to D-76. Standard film developer used as stock solution, one-shot or replenishable. Gives normal speed and average graininess. Supplied in powder form.

Developing Tank ::. A small plastic or stainless steel tank, into which 35mm film roll or 120 roll film is placed on spiral reels, for processing. Lightproof tops allow solutions to be poured in and out in daylight.

Dish development ::. Method of development used for processing single sheet, cut film or paper by immersing in a shallow dish of developer and agitating by rocking the dish.

Emulsion ::. The light sensitive surface layer of film and paper. Usually consists of silver halides in gelatin. It’s put there to protect and hold the light-sensitive material, usually silver halides in gelatin, in which the image is formed on film and photographic papers.

Easel ::. Sits on baseboard of enlarger and holds paper flat and in position. Two or four adjustable blades adjust to fit different sizes of paper or border. Use to crop during printing.

Edge number ::. Film has a clear unexposed strip running the length of both edges. This strip, called the rebate, is pre-exposed with edge numbers to identify each frame as well as a product code to identify the film make and type.

Emulsion Side ::. The side of the film coated with emulsion. In contact printing and enlarging, the emulsion side of the film-dull side-should face the emulsion side of the photo paper-shiny side.

Enlarger ::. Used to project a magnified image onto printing paper. Comprises a lamp house, negative carrier and lens assembly which can be raised or lowered on a column to project an image onto a baseboard.

Film leader ::. Shaped portion at the start of 35mm film used to aid loading.

Film Leader Retriever ::. Device which can be inserted into a 35mm cassette to pull out a film leader which has been fully wound in. Useful if you want to re-use film that was removed mid-roll. Also helpful during film processing.

Fiber Based Paper ::. Photographic paper without a resin (plastic) coating. Processing times are longer than for other papers, but the paper is probably more archival permanent than resin coated papers.

Film Characteristic Curve: This curve describes a graphical relationship between the logarithm of the exposure value (horizontal axis) and density (vertical axis) of film. Each brand of film may exhibit a different characteristic curve.

Fixer, Fix ::. A chemical solution used after stop bath to remove any unexposed silver.

Flashing ::. Pre-exposing the paper to a much diffused white light in order to reduce the contrast level between the highlights and shadows and extend the tonal range. Other tonal techniques include burning, dodging, toning, and bleaching.

Flat Negative ::. A flat negative is low in contrast, usually caused by underexposure or underdevelopment of film. Flat light shows no change in brightness value throughout the entire scene.

Fibre-based Paper ::. A printing paper that doesn't’t have a resin coated surface. It takes much longer to wash and dry but the results can look better and it has better archival qualities.

Focus Magnifier ::. Device to magnify the optical image and aid visual focusing.

Gelatin ::. The medium used on photographic materials as a means of suspending light-sensitive silver halides.

Grades, Paper Grades ::. A classification system for specifying the degree of paper contrast, ranging from 0 (very soft) to 5 (very hard).

Grain ::. Clumps of silver-halide grains in film and paper that constitute the image. These grains are produced both in the exposure process (film grain) and in the development process (paper grain). Unlike film, the grain in printing paper is largely responsible for the image tone. Graininess is most noticeable in even, mid-tone areas of a print.

Hard Developer ::. A paper developer that can be used alone or in combination with other developers (two-bath development). When used alone, a hard developer can produce a wide range of tones. Contrast can be varied by changing paper grades, changing filtration, or using a softer developer to obtain intermediate contrast grades.

Highlight Separation, Highlights ::. Important bright areas (highlights) of a scene in which detail must be recorded (exposed) onto the film. Highlights are represented on a negative by dense deposits of black metallic silver, reproducing as the bright areas on a print (also see shadow detail).

Hypo Clear ::. Chemical solutions used to speed up the efficient removal of fixer from the prints in subsequent water washings of the prints.

Incident Light ::. Light falling onto a surface, not reflected from it (reflected light).

Inter negative ::. An inter negative is made by duping a positive slide or transparency onto color negative film. This inter negative can then be printed on color negative (Type “C”) paper. Negative printing materials have lower contrast than do positive papers, but this inter negative process will reduce overall sharpness and color saturation.

Intensification: Chemical method of increasing the density of the photographic image. It is only suitable for treating negative materials and works better on negatives that have been underdeveloped rather than underexposed.

Jug ::. A container for water, you fill her up and pour out to use whenever the need be.

Kettle ::. Invaluable piece of equipment when it’s all going wrong. Use to make tea or coffee to accompany quantities of chocolate.

Latent Image ::. The invisible image that is formed when the silver halide compounds in film are struck by light. Upon development, this image, or series of light and dark tones, is made manifest.

Line Film ::. A high contrast film which after correct development, gives negatives of black and white only- (with no gray areas).

Masking ::. A technique for controlling contrast in the printed image.

Mackie Line ::. Is an effect sometime found on a negative or print, in which a light line forms along the boundaries of the darkest image areas. It may also be caused during processing by the diffusion of exhausted developer, lack of agitation, or by Solarization.

Negative Carrier ::. Removable holder which fits between lens-board and lamp-house of an enlarger. Holds negative flat and in a fixed position. Can be glassed or glassless. Glass prevents negatives popping or buckling from heat of the lamp but introduces more surfaces for dust to settle on.

Ortho ::. Short for Orthochromatic – a high contrast film that’s sensitive to all color other than red and deep orange. As a result these can be handled under red safelight conditions and are designed primarily for reproducing halftone images or artistic black and white shots that have few mid tones.

Opacity ::. The degree to which an object blocks light. Technically, opacity is expressed as a ratio of the incident light to the transmitted light.

Posterization ::. Photographic technique using a number of tone separated negatives which are printed on high contrast material. A master negative is made by printing these in register. The final print from this contains selected areas of flat tone in place of continuous tone. This effect is sometimes incorrectly referred to as Solarization.

Print Tongs ::. Plastic tongs, often with rubber tips, used to lift prints and transfer between developing trays without allowing solutions to come in contact with skin.

Pearl Surface ::. There are two surfaces of Ilfochrome Classic printing material. Pearl is a slightly textured matte finish on a resin-coated paper base. It is less susceptible to reflections and fingerprints than the glossy surface and is easier to mount, but is only available in one (medium) contrast grade. It is not considered archival.

Paper Characteristic Curve ::. This curve describes a graphical relationship between exposure values (horizontal axis) and image density (vertical axis) of a printing paper. Each brand of paper may have a different initial characteristic curve and graded paper curves will be different than variable contrast paper curves. The shape of the curve can be altered by different developers, development times, temperatures, and toning.

Photogram ::. Where an image is created by placing an object directly onto printing paper and exposing it to a light source. Many photographers and artists have tried this technique including pioneers Thomas Wedgwood and Fox Talbot along with the Surrealist, Man Ray.

Pull-Processing ::. A technique used to reduce subject contrast and film speed by overexposing and under developing.

Push-Processing ::. A technique used to increase contrast and film speed by underexposure and over development, also known as up-rating.

Reflected Light ::. Light bounced off a subject, not falling on it (incident light).

Resin Coated Paper ::. Photographic paper with the emulsion coated in a resin (plastic). Processing times are shorter than for other papers, but the paper may not be as archivally permanent (see other paper types: variable contrast, graded contrast, fiber based).

Reducer ::. A chemical that’s used to reduce the density of a processed negative, often referred to as Farmer’s Reducer.

Replenisher ::. A solution used to top up and maintain part used processing chemicals. This is more economical because you can extend the life of previously used stock by replacing a measure of it.

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.

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.

Squeegee ::. Tool with rubber blades or rollers, used to squeeze water out of wet prints.

Shadow Detail ::. Important dark areas (shadows) of a scene in which detail must be recorded (exposed) onto the film. Shadows are represented on a negative by sparse deposits of black metallic silver, reproducing as the dark areas on a print (also see highlight separation).

Silver Halides ::. The light sensitive element of common photographic emulsions. Usually one of these silver halide compounds: silver bromide, silver chloride, or silver iodide.

Soft Developer ::. A paper developer that can be used alone or in combination with other developers (two-bath development) to achieve more subtle contrast control. Commonly used with graded papers to achieve intermediate grades, that is, to soften the contrast.

Stop Bath ::. Acid solution used after development to instantly arrest further development.

Safelight ::. Orange or red light used in a darkroom. Gives out light of a wavelength to which photographic paper is relatively insensitive. Safe lights are not actually safe. Leave paper exposed to a “safe-light” close enough or for long enough and the paper will fog.

Step Wedge ::. Printed series of density increases, in regular steps from transparent to opaque. It’s a method of making exposure tests when enlarging.

Sulfide Toning: Conversion of a black metallic silver image into a brown dye image. Usually known as sepia toning.

Test Strip ::. A strip of printing paper that is given a series of incremental exposure times (such as 3, 6, 9, 12 seconds) in order to determine the ideal base exposure time.

Tonal Values, Tonal Range ::. The range of tones (zones) within a particular area or scene.

Tone ::. A black and white photograph is made up of a series of gray tones. Controlling these tones allows us to control the nature of the photograph, both emotionally and technically. Since the number of gray tones is quite large it needs to be broken down from a continuous range to a series of distinct zones. These zones make up what is known as the Zone System.

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.

Toning ::. Soaking the print in selenium to help darken the black areas and give the print an overall feeling of “richness”. Other tonal techniques include burning, dodging, flashing, and bleaching.

Transmitted Light ::. Light that is passed through a transparent or translucent medium.

Two-Bath Development ::. The use of two different developers to alter the contrast in a print.

Thick Negative ::. Antique term used to describe a dense negative.

Thin Negative ::. Antique term used to describe a negative lacking in density.

Universal Developer ::. Name given to a number of developing solutions, usually MQ, indicating that they can be used for processing films and papers.

Variable Contrast (printing 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.

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.

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.

Wetting Agent ::. A few drops added at the end of washing reduce surface tension of water preventing droplets forming on surface during drying. As drops dry they leave a roughly circular “drying mark” of residue from the water.

Warm Tone ::. The look or mood of a print or slide that tends toward the amber, or yellow/red. In black and white prints it’s a brown or sepia-toned print, or a brown-black printing paper.

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.

Working Solution ::. Is a liquid chemical that has been mixed and diluted for use.

X Marks the Spot ::. A place in the darkroom to stand and twiddle your thumbs on.

Yawn ::. A yawwwnnnnnnnnnn is a yaaawwwnnnn.

Zone System ::. Invented by Ansel Adams and Fred Archer in the 1940’s, the Zone System is a means of making an exposure in a scientifically accurate manner. The Zone system breaks the black and white tones into 10 zones or “scales” ranging from complete black with no visible texture (Zone I) to pure white with no visible texture (Zone X). Zone V is the middle gray tone. The Zone System of Exposure is widely used today.