UPMSP Vocational Colour Photography flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Additive colour mixing

Combining red, green and blue light to form other colours; equal amounts of all three produce white. It governs screens, LEDs and stage lighting rather than ink or dye.

Colour temperature

A measure in kelvin of the hue of a near-white source: roughly 3200 K for tungsten, 5500 K for daylight and 6500 K for overcast sky. Lower values look warmer.

Metamerism

A condition where two colour samples appear to match under one illuminant but differ under another, because their spectral reflectance curves are not identical.

Inverse-square law

Illuminance from a point source decreases with the square of distance. Doubling lamp-to-subject distance reduces light to one quarter, changing exposure and falloff.

f-number

The ratio of focal length to entrance pupil diameter. Each full stop such as f/2 to f/2.8 halves the light reaching the sensor or film.

Hyperfocal distance

The focus distance at which depth of field extends from half that distance to infinity. It depends on focal length, aperture and chosen circle of confusion.

Crop factor

The ratio of a full-frame diagonal to a smaller sensor's diagonal. It changes equivalent field of view and depth of field but not exposure per unit area.

Depth of field

The zone of acceptable sharpness around the focus plane. It increases with smaller aperture, shorter focal length and greater focus distance, and shrinks with magnification.

Stop bath function

An acidic bath that neutralises alkaline developer and halts development immediately. It protects the fixer from carry-over and helps maintain consistent density.

C-41 process

The standard colour negative process: develop, bleach, fix or blix, wash and stabilise, usually near 37.8 C. Temperature and time errors shift colour balance and density.

E-6 process

The colour transparency process using a first developer, reversal bath, colour developer, bleach and fix. It yields slides and tolerates less push processing than negative film.

Reciprocity failure

The loss of effective exposure at very long or very short exposure times, requiring increased time and often colour-correction filtration. It affects film more than digital sensors.

Exposure value

A number combining aperture and shutter: EV equals log base two of N squared over t. It allows comparison of exposure settings independent of ISO.

Sunny-16 rule

A guide for direct sun: at ISO 100 and f/16, use a shutter near 1/100 second. Open one stop for hazy sky and two for overcast.

Incident metering

Measuring light falling on the subject with a dome meter at the subject position. It is independent of subject reflectance and avoids errors from bright or dark subjects.

Exposure compensation

A control that shifts the meter's assumed middle grey in automatic modes. Positive values brighten the image; negative values darken it.

Lighting ratio

The ratio of key plus fill light to fill alone, written as 2:1, 4:1 or 8:1. Each extra stop of fill difference doubles the ratio and lowers contrast.

High-speed sync

A flash mode that pulses light to stay lit across a fast shutter curtain, allowing wide apertures in bright conditions beyond the normal sync speed.

Rembrandt lighting

A key-light position producing a small triangle of light under the shadow-side eye, with the light roughly 45 degrees to the side and above the subject.

Flash duration

The time a strobe emits light, typically a fraction of a millisecond. It freezes motion independently of shutter speed in studio work.

Dodging and burning

Local darkroom controls: dodging reduces exposure to brighten an area, while burning adds exposure to darken it. Both use shaped cards or hands above the paper.

RA-4 process

The standard colour negative paper process using developer, bleach-fix and stabiliser, usually in a roller transport machine near 35 C. Exhausted chemistry causes crossover.

Ring-around test

A series of test prints with varying filtration and exposure made before final printing. It establishes correct colour balance and density systematically.

Soft proofing

Simulating a printer and paper profile on a calibrated monitor so colour and contrast can be judged before printing, using the same rendering intent as output.

Bit depth

The number of levels per colour channel. Eight-bit gives 256 levels and sixteen-bit gives 65,536, reducing banding during heavy tonal edits.

Raw file advantage

Raw capture retains unprocessed sensor data, allowing non-destructive white balance, exposure recovery and wider editing latitude than in-camera JPEG files.

Monitor calibration

Setting a display to a known target, such as D65 white point, 120 candelas per square metre and gamma 2.2, so colour judgements are reliable.

Rule of thirds

A composition guide placing important elements near the intersections of a frame divided into thirds. It often creates more dynamic balance than centring.

Leading lines

Linear elements such as roads, railings or shadows that draw the viewer's eye through the frame and create a sense of depth and direction.

Portrait focal length

On full frame, roughly 85 to 135 mm is preferred for portraits because it reduces perspective distortion and flatters facial proportions at comfortable working distance.

Lens fungus prevention

Storing optics below about 60 percent relative humidity with silica gel in a dry cabinet prevents fungal growth, which etches coatings permanently.

Usage licence

A written grant of specific rights to use an image, such as media, territory, duration and exclusivity. It is separate from the creative fee and copyright ownership.