Film, Darkroom & Historic Processes — 60 Terms Defined

E-6 Process Film, Darkroom & Historic Processes minutes at °C The standardised chemical process for developing colour reversal film into positive transparencies.

Emulsion Film, Darkroom & Historic Processes µm The light-sensitive coating on film or paper, consisting of silver halide crystals suspended in gelatin.

Enlarger Film, Darkroom & Historic Processes × magnification A darkroom device that projects a negative onto photographic paper to produce a print larger than the original. Magnification = image size / negative size

Enlarging Lens Film, Darkroom & Historic Processes mm A lens optimised for projecting a flat negative onto flat paper at close range.

Fibre-based Paper Film, Darkroom & Historic Processes g/m² Photographic paper whose emulsion is coated directly onto a paper base with no plastic layer.

Film Film, Darkroom & Historic Processes mm / format A flexible transparent base coated with a light-sensitive emulsion, which records an image chemically rather than electronically.

Film Base Film, Darkroom & Historic Processes µm The transparent support that carries the emulsion, historically nitrate or acetate and now usually polyester.

Film Grain Film, Darkroom & Historic Processes RMS granularity The visible texture produced by clumps of developed silver, which becomes more apparent with faster films and greater enlargement.

Film Speed Film, Darkroom & Historic Processes ISO A film's sensitivity to light, rated on the ISO scale and formerly as ASA or DIN. ISO arithmetic = 2^((DIN−1)/10)

Fixer Film, Darkroom & Historic Processes minutes A solution that dissolves the undeveloped silver halide, making the image permanent and no longer light-sensitive.

Infrared Film Film, Darkroom & Historic Processes nm Film sensitised beyond the visible spectrum into the near infrared, producing distinctive tonal reversals.

Latent Image Film, Darkroom & Historic Processes The invisible record formed in an emulsion by exposure, before development makes it visible.

Orange Mask Film, Darkroom & Historic Processes The integral orange-coloured layer in colour negative film that corrects for imperfections in its dyes.

Orthochromatic Emulsion Film, Darkroom & Historic Processes nm A black and white emulsion sensitive to blue and green but not to red light.

Panchromatic Emulsion Film, Darkroom & Historic Processes nm A black and white emulsion sensitised to all visible wavelengths, rendering colours as plausible grey tones.

Paper Grade Film, Darkroom & Historic Processes grade (0-5) A number describing the contrast of a graded photographic paper, from soft grade 0 to very hard grade 5.

Photogram Film, Darkroom & Historic Processes An image made by placing objects directly on photographic paper and exposing it to light, without a camera.

Photographic Paper Film, Darkroom & Historic Processes g/m² Paper coated with a light-sensitive emulsion, used to make prints from negatives.

Platinum Print Film, Darkroom & Historic Processes A contact printing process using platinum or palladium salts, giving an exceptionally long tonal scale and great permanence.

Pull Processing Film, Darkroom & Historic Processes stops Rating a film below its nominal speed and shortening development to compensate.

Push Processing Film, Darkroom & Historic Processes stops Rating a film above its nominal speed and extending development to compensate.

Reciprocity Failure Film, Darkroom & Historic Processes seconds The breakdown of the reciprocity law at very long or very short exposures, where film needs more light than calculation predicts. t_corrected = t^p

Resin-coated Paper Film, Darkroom & Historic Processes g/m² Photographic paper sealed between thin polyethylene layers so chemistry cannot penetrate the base.

Safelight Film, Darkroom & Historic Processes nm A darkroom lamp emitting only wavelengths to which the material in use is insensitive.