UPMSP Vocational Colour Photography key terms

A measure in kelvin of how warm or cool a light source appears, ranging from about 2000 K for candlelight to 6500 K for daylight, used to match film or sensor balance to the light.

The creation of colour by mixing red, green and blue light in varying proportions, as in a monitor or an enlarger head, where equal amounts of all three produce white.

The creation of colour by removing wavelengths from white light using cyan, magenta and yellow dyes or filters, the principle behind colour negative film and photographic printing.

Pairs of colours that lie opposite each other on a colour wheel, such as red and cyan or blue and yellow, which neutralise each other when combined in the correct proportions.

An unwanted overall tint in an image caused by a mismatch between the light source and the film or sensor balance, or by a processing fault.

A coloured filter placed over the lens to absorb part of the spectrum and bring the light reaching the film closer to its rated balance, for example an 85B for tungsten film in daylight.

The adjustable opening in a lens that controls how much light passes through, expressed as an f-number; each full stop halves or doubles the light reaching the film or sensor.

The zone of acceptably sharp focus in front of and behind the subject plane, which shrinks as aperture widens, focal length increases or camera-to-subject distance shortens.

The focus distance at which everything from half that distance to infinity appears acceptably sharp at a given aperture and focal length, a standard technique for landscape work.

The loss of effective film speed and the shift in colour balance that occurs at very long exposures, requiring increased exposure time and filtration to compensate.

The invisible pattern of exposed silver halide grains formed in film by light, which becomes a visible image only when the film is developed.

The alkaline processing solution that converts exposed silver halide grains into visible metallic silver, and in colour film also forms dye images in proportion to the silver produced.

A dilute acid solution used between developer and fixer to halt development immediately and protect the fixer from developer carry-over.

A solution, usually based on sodium or ammonium thiosulphate, that dissolves unexposed silver halide so the image becomes stable and insensitive to further light.

Film whose emulsion layers form a negative image in complementary dyes, so that orange-masked negatives must be printed or scanned to produce correct positive colours.

The relationship between aperture, shutter speed and film speed or ISO, where changing one requires a compensating change in another to keep the same overall exposure.

The measurement of light reflected from or falling on a scene to determine exposure settings, using patterns such as centre-weighted, spot or evaluative measurement.

A card reflecting about 18 percent of incident light, used as a reference for reflected-light metering and for setting white balance in mixed or uncertain lighting.

The camera or film setting that defines which colour of light is treated as neutral white, so that neutral objects in the scene render without a colour cast.

The main light source in a portrait or still-life setup, placed to establish the direction of illumination, model the subject's form and set the dominant shadow pattern.

A secondary, usually softer light or reflector placed opposite the key light to open up shadows and reduce contrast without removing the modelling of the main source.

The numerical relationship between the intensity of light falling on the lit and shadow sides of a subject, often expressed as 2:1, 3:1 or 4:1 for portrait work.

A light placed behind the subject and angled towards the camera to create a bright outline that separates the subject from a dark background.

The adjustable light source on a colour enlarger containing cyan, magenta and yellow dichroic filters, used to dial in the filtration needed for correct colour balance in a print.

A small piece of printing paper exposed in steps at increasing times or filtrations and developed to judge the correct exposure and colour balance before making a full print.

A set of small prints made with graduated changes in one variable, such as magenta filtration, to identify the direction and size of the correction needed for a final print.

Local printing controls in which light is withheld from chosen areas with a mask or added to chosen areas through a hole, to adjust density within a single exposure.

An unprocessed camera file containing the sensor's original data, which must be converted with software where white balance, exposure and tone can still be adjusted with wide latitude.

A graph showing the distribution of tones or colour values in an image, used to judge clipping at the highlights and shadows and to guide exposure and editing decisions.

A file describing how a device such as a monitor, scanner or printer reproduces colour, allowing colour management software to convert values consistently between devices.

Simulating on a calibrated monitor how an image will appear when printed on a particular paper and printer, using their profile so adjustments can be made before printing.

A composition guide that divides the frame into a three-by-three grid and places important elements near the intersections or along the lines for a more balanced image.

A compositional element such as a road, river or shadow edge that draws the viewer's eye through the frame towards the main subject or a vanishing point.

Using elements in the foreground or at the edges of the picture to enclose and draw attention to the subject, adding depth and context to the composition.

The pleasing arrangement of colours in a picture, achieved through schemes such as analogous, complementary or monochromatic relationships between the dominant hues.

Stray light reflecting inside the lens that reduces contrast or produces bright artifacts, often avoided with a lens hood or controlled deliberately for effect.

A shade fitted to the front of a lens to block off-axis light that would otherwise cause flare and reduce contrast, especially in backlit or bright conditions.

A signed agreement in which a person grants permission for their identifiable image to be used for specified purposes, essential for commercial and stock photography.

The legal right of the creator of an original photograph to control reproduction and use of the image, which in most systems arises automatically on creation and can be licensed or assigned.

A written agreement granting a client specific rights to use an image, defining media, territory, duration and exclusivity, while the photographer retains copyright.