Glossary of Terms

Some of the terminology used in photographic ( and motion picture ) labs.

Anamorphic An optical compression system used for widescreen cinematography and occasionally photography. Normally used in cinema for Cinemascope movies, these images nominally have an aspect ratio of 2.40:1 and use special optical systems that compresses the image horizontally by two times for photographic capture. The image is then expanded by two times for projection.
Anti-Newton Glass Slide
A special type of glass used in certain slide mounts to avoid the ‘rainbow rings’ effect when projected – a phenomenon caused by intimate contact between the film and glass.
ASA American Standards Association, the exposure index denoting the film’s sensitivity (speed rating), the same number is used for ISO.
Aspect Ratio Figure given to the shape of an image in respect of height against width  i.e… the standard 35mm full frame film image (measuring 24mm x 36mm) has an aspect ratio of 1.5:1 whereas a 10″x8″ ‘shape’ has a ratio of 1.25:1 – For more, see our Aspect Ratio and Sizes page.
Base Side With reference to film, this is the side facing you when viewing negatives or transparencies. You’re actually viewing the image through the base. This is the opposite side to the emulsion.
BIPP The British Institute of Professional Photography – an industry body recognised throughout the world representing professional photographers and photographic laboratory technicians. See
Blow Up Term used for making copies larger than the original.
Blue A colour formed by mixing  Cyan and Magenta light. It is the complimentary colour to Yellow.
Bracketing To take a series of exposures of the same shot covering the ‘metered’ reading to assure the correct exposure has been taken.
Bulk Film Long film rolls used through special cameras and printers or reloaded into standard short length cassettes like 35mm.
Burning Term used for darkening selected areas while exposing and making a print (when printing negatives).
C-41 The standard colour negative film process today. Invented by Eastman Kodak to replace process C-22 when it was introduced globally in 1972.
Chromogenic Film and process system where images are formed in the film emulsion by dyes rather than silver grains (like colour negatives and colour slides). Usually chromogenic is used for colour but there are some B&W films like Ilford XP2 that require developing through the colour negative C-41 process.
Cine Film Motion picture film, for example…8mm, 9.5mm, 16mm, 35mm, 65mm and 70mm.
Clip Test A short piece of film removed from the front of 35mm rolls and the end of 120 / 220 rolls which is then processed to determine the film speed for the rest of the roll (to be pushed or pulled if needed).
Colour Grading (See grading).
Colour Scales Series of calibrated colour patches placed next to paintings, photographs etc… to aid proper reproduction  *as with grey scales.
Colour Temperature For correct colour results, it’s important to use the right film type for the lighting used  eg… ‘daylight’ balanced film for daylight and electronic flash or ‘tungsten’ balanced film for photoflood lamps. Expressed in degrees Kelvin ( daylight = 5500K  and  tungsten = 3400K ).
Colour Timing American term for colour grading (see grading).
Contact Printing Prints made by exposing negatives or transparencies in intimate contact with the printing paper (or film).
Continuous Processor Type of processor that transports film (or paper) rolls through the process and dryer in a continuously moving action from dark box or magazine to rolled take up.
Contrast Index (CI) This is an indicator for B&W film process control ‘aims’ sometimes referred to for Gamma and characteristic curves / contrast curves of B&W films.
Control Strips Sensitometrically exposed length of film or paper designed for process quality control within the lab.
Cross Processing A technique used for special effects photography. This involves shooting on the ‘wrong’ film for the intended process so to give varying results like false colours or strong contrasts.Note: all films give different results, so testing is highly recommended. *Cannot cross process B&W through colour chemistry or vice versa.
Cut Film An old term used for sheet film.
Cyan Colour formed by mixing Green and Blue light. It is the complimentary colour to Red.
Darkslide A light-tight sheet film carrier normally double sided (also know as a double darkslide) to enable sheet film to be used in a camera.
Densitometer Instrument used for measuring film or paper densities for process control purposes (usually control strips). Light transmission for film and light reflectance for paper.
Diffusion Light Source An illumination system used in enlargers and printers to help suppress some base surface scratches and dust on films. Inherently gives a slightly lower contrast light compared with condenser or point light source lamphouses.
Digital ICE An Eastman Kodak developed software for use in film scanners that helps suppress dust marks and scratches on film surfaces during scanning.
Dip and Dunk Processor Type of film processing machine that lifts and transfers films through the process and dryer at set cycle times. Also called ‘rack and tank’ processors.
Dodging A term used for holding back selected areas while exposing and making a print (when printing negatives).
Dupe Term used for duplicate transparencies or negatives. A direct positive copy from another positive or a direct negative from a negative made using a special low contrast fine grain film.See our 35mm and 70mm Dupe Services
E-6 The standard colour reversal film process today. It was invented by Eastman Kodak to replace process E-4 when it was introduced globally in 1976. See our E-6 Processing Services
Edge Code / Edge Numbers On film, these are not only used for identifying frames, but additional data includes information like film type and manufacturing batch numbers. Some motion picture films have digital code ‘bar codes’ for use in editing.
Enlarger Type of film projector used for making prints from negatives or transparencies etc… Many variations are available to take various film formats and to produce many different print sizes.
Enprint Small enlarged prints, usually the cheapest Develop & Print package size.  eg…6″x4″
Emulsion Side Reference to film, this is the side facing away from you when viewing negatives or transparencies. These ultra thin layers are the most delicate part of film, as it is the actual image itself.
Exposure Latitude All films have some latitude near the correct exposure, though some types like transparency film have very little ( approximately plus or minus half a stop ), whereas B&W film can have a wider latitude of a stop or more. Because of this, all negative films have the advantage of being corrected at the printing stage.
Fading Prints In reference to motion picture film prints from negatives, often referred to as ‘pink prints’, these older film stocks ( pre 1982 approx ) tend to lose mainly the cyan and yellow layers fading over time and leaving only the magenta layer behind.
Film A flexible acetate or polyester based material used for recording images by exposure to light then processing.
Film Recording Transparency or negative ‘filmouts’ are produced using a computer based camera system where digital image files are ‘written’ out to film.Some recorders use lasers while others use a cathode ray tube ( CRT ) as an imaging device. In motion picture use, practically every major production will utilise a film recorder when preparing master negatives.
Flashing Technique to artificially lower the film’s overall contrast. This is done by exposing film to a very brief controlled light level prior to photography, thus lightening the black level of the emulsion.
FPS Frames per second.
FTP File Transfer Protocol, a system for sending large image files over the internet. This has largely been superseded by upload websites such as and dropbox etc…
Gamma With reference to B&W film, see Contrast Index.
Grading In printing (film or paper) this is a term used for correcting colour and density to make final prints / dupes.
Green A colour formed by mixing Cyan and Yellow light. It is the complimentary colour to Magenta.
Grey Scales Series of calibrated monochrome tones or ‘step wedges’ placed next to paintings, photographs etc.. to aid proper reproduction. *as with colour scales.
Halation Flare on film caused by very bright light hitting the film and reflecting within its layers. Most films are made with an
anti-halation backing layer to help suppress this. Halation is most likely to occur with high contrast light photography such as night shots with streetlamps etc…
Half Frame A format using standard 35mm film but using only half the normal frame area of 24mm x 18mm (instead of 24mm x 36mm) thus giving double the amount of exposures (72 frames on a roll of 36).
Halfplate An obsolete plate film format measuring 4.25″ x 6.5″
Ilford Multigrade Ilford’s B&W resin coated printing paper that can produce several contrast grades or levels ( from 00 to 5 ) *suitable for a wide range of different negative film densities and qualities.
Infrared (I-R) Band of invisible wavelengths that can be used in specialist or special effects photography including B&W and false colour photography. Contrary to belief, you cannot photograph the heat portion of I-R wavelengths with Infra-Red film.
Internegative A negative made from a positive ( slide or transparency ) which is then used to make positive prints.
JPEG Files A universally used file type for shooting, printing and distributing images. Data is compressed to allow for smaller files thus saving memory space.
Kodachrome A colour reversal film and process invented by Eastman Kodak in 1935. This unique system differs completely from other colour reversal processes in as much as the film is actually a complex multilayered black and white emulsion that has its colour layers formed during processing. See K-14.
K-14 The last version of Kodachrome reversal film and process.A technically complicated process originally provided by Kodak. The last lab ( Dwayne’s in the USA – an independant ) offered the service till the end of 2010. It has now been totally discontinued and resigned to history. K-14 as a reversal process has been replaced with process E-6.
Lantern Slides Old and obsolete slide formats that were generally made by photographers themselves. These were usually made by printing B&W negatives on to B&W print film, then mounted between glass slide mounts. They were commonly used in lecture theatres. (sizes varied up to 3.25″ x 3.25″).
Large Format Refers to all sheet film formats such as 5″x4″ or 10″x8″
Latent Image An invisible image recorded on film when exposed, prior to it being made visible by processing.
Lightbox A film viewing device such as a lightbox (with a magnifier) is very useful for inspecting negatives, and is especially useful for transparencies if the illumination is daylight colour balanced and at the correct light level.
Magenta Colour formed by mixing Blue and Red light. It is the complimentary colour to Green.
Medium Format Refers to film formats using 120, 220 or 70mm roll film.
Miniature Format An old reference to small film formats such as Minox, pocket camera films and 35mm.
Minilab Type of printer, processor or combination of both. These machines are designed for fast turnaround of work using rapid access (RA) ‘wash-less’ type processes.
Motion Picture Film Cine or movie film, precision perforated, slit and supplied in long rolls ( usually 50ft, 100ft, 400ft and 1000ft for cameras ) and up to 6000ft for printers.
Multigrade General term for variable contrast chemicals and papers used in B&W paper processing.
Newton Rings ‘Rainbow rings’ effect commonly seen when using glass slide mounts. This effect is produced by intimate contact between film and glass, so anti-Newton glass mounts should be used.
Nitrate Film Cellulose Nitrate film stocks were used for producing 35mm cinema prints pre mid 1950’s. It was an extremely flammable film base that disintegrates over time and produces cyanide gas as it breaks down. Now superseded with acetate and polyester ‘safety film’ bases.
Optical Printing To produce prints or dupes by projecting the original on to paper or film.
Optical Works Term used for various adjustments and effects made when copying onto film.
Orthochromatic Film or paper emulsions that’s only sensitive to the blue and green part of the light spectrum. Ortho materials can be handled in a darkroom using red safelights.
Panchromatic Film or paper emulsions that are sensitive to all visible colour parts of the light spectrum. Panchromatic materials must be handled in total darkness or under Infra-Red safelighting with Infra-Red viewers.
Perforations Precision punched holes along the film’s edge, used for mechanically transporting and winding film through cameras, magazines, printers and projectors.
Plate Reference to film, these are film emulsions coated on optically flat glass. Though not used for general photography anymore, there are special emulsions made for scientific, nuclear and astronomical photography.
Polymax RT Kodak B&W paper developer designed for use in roller transport processing machines at high temperature.
Process Control Term used for quality control within a processing laboratory. This usually involves processing and measuring control strips ( densitometry ), as well as monitoring temperatures, specific gravity and pH levels ( depending on the process ).
Projection Quality A colour graded copy which is good enough for projection use. This is an economic option to Reproduction Copies.
Push / Pull Processing An accurately controlled over or under development used for changing film speeds either on purpose (to boost  a slow film in low light situations), or to save film because of wrong meter settings used by accident. In colour processing, the density, contrast and colour balance will change. With B&W processing, the density and contrast changes. In both cases grain structure changes too. * more adjustment = less quality.
Q-plates These are specialist glass plate films for use in mass spectrography.
Quarter plate This is an old obsolete film and paper size measuring 3.25″ x 4.25″
Quickslide slide mounts A type of 35mm plastic slide mount made by Gepe in Germany and used in machine mounting.
Radiation Electromagnetic wavelengths ie.. light, heat and x-rays. Most will expose ( fog ) sensitive photographic materials such as film.
Rapid Access (RA) Term used for fast working chemicals in processing. eg…process RA-4 is the standard colour paper process today which takes approximately four and a half minutes to develop and dry a print after exposure.
RAW Files An image file as captured by a digital camera or scanner prior to it being further processed for viewing. (not necessarily accessible on all digital cameras). It can be regarded as a ‘digital negative’  ie…Nikon NEF files.
Red Colour formed by mixing Magenta and Yellow light. It is the complimentary colour to Cyan.
Reduction Term used for making copies smaller than the original.
Release Print A motion picture film print designed for projection in a cinema. These are manufactured on high speed contact printers from negatives, internegatives or duplicate negatives.
Reproduction Copy A fully colour corrected copy which is as close as possible matched to an original – given the limitations of copying techniques.
Retouching An after treatment used for fixing technical problems such as removing spots and blemishes from prints and negatives, or as an artistic ‘tool’ for changing an image.
Reversal As in reversal film means to produce a positive image rather than a negative one  ie…unexposed parts of the material will come out black while exposed parts will be light.
Roller Transport
Type of processor that transports film or paper rolls or sheets through the process and dryer using rollers in a continuously moving action from dark box or magazine to a rolled take up – without the need to splice onto leaders.
Safety film All film manufactured today is on a ‘safety film’ stock. Unlike 35mm film produced pre-mid 1950’s for motion picture use that was coated on a Cellulose Nitrate base and is highly flammable. Emulsions are now coated on acetate or Polyester bases. Even though Nitrate film hasn’t been used for over half a century, today’s films are still referred to as ‘safety film’.
Scanning To scan ( digitise ) films or photographs so the image can be adjusted and manipulated. Digital files are then used for archiving or printing.
Sheet Film Film supplied in sheets eg…5″x4″ or 10″x8″. These emulsions are usually coated on a thicker base than roll films to help keep flatness during exposure and printing.
Single Light Term used to describe a fixed overall exposure, colour balance or contrast setting to bulk print film in one go ( without full individual frame correction ).
Snip Test A short piece of film removed from the front of a roll which is then processed to determine the film speed for the rest of the roll (to be pushed or pulled if needed). Same as a Clip Test.
Stops In processing, this refers to f stop differences when adjusting film speeds…ie 100 ISO film can be rated at 200 ISO if pushed one stop.
Technicolor Dye Transfer Prints Also known as IB Technicolor. An obsolete motion picture printing process where images were printed photographically and mechanically ( like modern day colour offset printing ) layer by layer giving highly saturated non fading colours. This process produced prints that were highly stable and with a unique colour gamut and wide density range giving ‘the Technicolor look’. It was mainly used for manufacturing 16mm and 35mm movie release prints.
TIFF Files An industry standard file type for distributing high quality scanned images or finished photographic files. These contain more information than jpg files and take up more memory space.
Transparency Term used for a positive image film. Viewed either by diffused backlighting ( on a lightbox ) or by projection.
Ultraviolet Or UV, an invisible wavelength that can affect certain photographic materials if left unfiltered.
Variable Contrast As in black and white printing paper. see Multigrade.
Vignetting either a technical fault  in the optical system where the whole image isn’t equally illuminated ( this can be a normal ‘characteristic’ of some wide-angle lenses ), or a deliberately produced artistic effect where the image corners are darkened.
Wet Gate Technique used for suppressing scratches and abrasions on film when printing. A special liquid with the same refractive index as the film’s base is ‘painted on’ filling in scratches and making them invisible during printing.
Wholeplate This is an old obsolete film and paper size measuring 6.5″ x 8.5″
Widescreen Motion picture term. Generally an aspect ratio wider than 1.37:1
XPan A ‘true’ panoramic 35mm film format used exclusively by Hasselblad. It has an image size of 24mm x 53mm effectively giving medium format quality. Other 35mm panoramic sizes are available, notably Russian Holga cameras. (not to be confused with panoramic settings used on 35mm compact cameras  as these use a masking system on a standard 24mm x 36mm frame).
X-Rays Radiation capable of fogging photographic film. Care should be taken to avoid scanning films through airport X-Ray machines. Although many modern scanners use low doses, you should remember it does have an accumulating effect. After processing, light or dark patches and lines can show up all over on films often ruining pictures.
XTOL film Developer A modern high grade Kodak B&W negative film developer.
Yellow Colour formed by mixing Red and Green light. It is the complimentary colour to Blue.
Zoo A place where some animals are taken to live, often without being asked first! Also occasionally useful for photography.