UPMSP Vocational Colour Photography cheat sheet

Visible spectrum spans roughly 380-700 nm; violet at the short end, red at the long end.

Additive primaries: red, green, blue. Equal RGB light yields white; R+G=yellow, G+B=cyan, R+B=magenta.

Subtractive primaries: cyan, magenta, yellow. Each subtracts its complementary additive colour from white light.

Colour temperature: 3200 K tungsten, 5500 K daylight/D50, 6500 K overcast/D65; lower K is warmer, higher K is cooler.

Correlated colour temperature (CCT) plus tint (green-magenta axis) fully describes a near-white source; CCT alone does not.

Hue is the colour name, saturation the purity, lightness/value the brightness; HSL and HSV differ in how lightness is defined.

Metamerism: two samples matching under one illuminant but not another; caused by different spectral reflectance curves.

Inverse-square law: illuminance falls as 1/d squared, so doubling lamp-to-subject distance cuts light to one quarter.

Colour constancy lets the eye neutralise a cast; a meter or neutral reference does not, so verify neutrals objectively.

Focal length, aperture and focus distance set field of view, exposure and depth of field together; change one and recheck the others.

f-number = focal length / entrance pupil diameter; each full stop (f/1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22) halves the light.

Depth of field grows with smaller aperture, shorter focal length, greater focus distance; shrinks with magnification.

Hyperfocal distance H = f squared / (N x c) + f, where c is the circle of confusion; focus at H for sharpness from H/2 to infinity.

Diffraction softening increases as aperture shrinks past roughly f/11 on full frame; balance against DOF needs.

Telephoto compression and wide-angle expansion are perspective effects of camera-to-subject distance, not of the lens itself.

Crop factor multiplies focal length and f-number for equivalent field of view and DOF; exposure per unit area is unchanged.

Shutter speeds follow 1/1000, 1/500, 1/250, 1/125, 1/60, 1/30 s; each step doubles exposure time and motion blur.

Lens coatings cut flare and raise transmission; a scratched front element mostly lowers contrast rather than sharpness.

Black-and-white development: developer reduces exposed silver halide to silver; stop bath halts development; fixer dissolves unexposed halide.

Standard B&W sequence: pre-soak (optional), develop, stop, fix, wash, wetting agent, dry; temperature control within +/-0.5 C matters.

Development is time-temperature-concentration dependent: pushing time or temperature raises density and contrast and grain.

C-41 colour negative: develop ~3:15 at 37.8 C, bleach, fix (or blix), wash, stabilise; deviations shift colour balance and density.

E-6 transparency: first developer, reversal bath, colour developer, pre-bleach, bleach, fix, final rinse; slide film tolerates less push than negative.

RA-4 colour paper processed in roller transport at about 35 C; chemistry exhaustion shows as crossover and weak blacks.

Film speed ISO combines arithmetic (linear) and logarithmic (DIN) scales; doubling ISO halves required exposure.

Grain and acutance trade off: fine-grain developers (e.g. low-pH, solvent types) soften edges; high-acutance developers increase apparent sharpness.

Chemical safety: store developers and fixers separately, never mix acid stop with hypo, and neutralise spills before disposal.

Exposure value EV = log2(N squared / t), where N is f-number and t is shutter time in seconds; EV 15 approximates bright sun.

Reflected-light meters assume 18% grey; a white subject reads high and a black subject low, so adjust by metering a grey card or bracketing.

Incident metering measures light falling on the subject and is unaffected by subject reflectance; use a dome at the subject position.

Sunny-16 rule: at ISO 100 and f/16, shutter ~1/100 s in direct sun; open one stop for hazy, two for overcast.

Exposure compensation in automatic modes shifts the meter's assumed grey; +EV brightens, -EV darkens.

Histogram clipping at either end loses detail; ETTR (expose to the right) maximises data but must not clip highlights.

White balance set by source: tungsten preset ~3200 K, daylight ~5500 K, flash ~5500-6000 K, shade ~7000 K.

Grey-card white balance: fill frame with card under the actual light, set custom WB, then recheck exposure.

Reciprocity failure at long exposures (generally >1 s on film) needs increased time and often colour-correction filtration.

Key, fill, background and hair/rim lights form the classic four-light setup; key defines form, fill controls contrast ratio.

Lighting ratio = key + fill : fill; 2:1 is flat, 4:1 moderate, 8:1 dramatic; each stop of fill difference doubles the ratio.

Soft light comes from large apparent source size relative to subject; move the modifier closer or enlarge it to soften shadows.

Inverse-square law governs falloff: a light twice as far gives one quarter the intensity, so background separation changes with distance.

Butterfly, loop, split and Rembrandt are key-light positions defined by nose-shadow shape and catchlight placement.

Sync speed caps flash shutter speed; high-speed sync (HSS) pulses the flash to allow wider apertures in bright light.

Flash duration, not shutter speed, freezes motion in studio flash work; short durations stop action.

Colour temperature mismatch between flash (~5500 K) and tungsten (~3200 K) needs gels or a custom white balance.

Location safety: sandbag stands, tape cables, check circuit load, and avoid mixing water with mains-powered strobes.

RA-4 printing uses cyan, magenta and yellow filtration to correct colour casts; more filtration adds that colour, less removes it.

Ring-around test prints a step wedge to establish correct filtration and exposure before final prints.

Density (exposure) is set by aperture and time; colour balance is set by filtration; adjust one variable at a time.

Dodging reduces exposure locally (brightens); burning adds exposure (darkens); use cards or hands above the paper.

Safelight must match paper sensitivity: RA-4 papers are handled in total darkness or with specified sodium-vapour safelights.

Paper contrast in B&W is graded or variable-contrast; VC papers respond to magenta/yellow filtration on the enlarger.

Test strips at intervals of 1/2 or 1 stop reveal correct base exposure before colour balancing.

Print washing and drying affect permanence; residual fixer causes yellowing, so wash to specification.

Enlarger alignment and lens quality limit sharpness; stop down two stops from wide open for best results.

Work in a wide-gamut space (Adobe RGB or ProPhoto RGB) for editing; convert to sRGB for web delivery.

Bit depth: 8-bit gives 256 levels per channel; 16-bit gives 65,536, reducing banding in heavy edits.

Raw files retain sensor data and allow non-destructive white balance and exposure recovery; JPEG bakes in settings.

Colour management needs a profile for camera, monitor and printer; soft-proofing simulates print output on screen.

Histogram and clipping warnings guide tone edits; use curves for contrast and levels for black/white points.

Sharpening is best applied in stages: capture sharpening, creative sharpening, output sharpening for the medium.

Layers and masks enable local adjustments without altering pixels; adjustment layers keep edits reversible.

Monitor calibration to a target (e.g. D65, 120 cd/m2, gamma 2.2) is the basis for reliable colour judgement.

Metadata (EXIF/IPTC) preserves copyright and shooting data; embed it before delivery.

Rule of thirds places key elements on intersection points; centred symmetry is a deliberate alternative.

Leading lines, framing, and negative space direct the eye and create depth.

Balance can be symmetrical (formal) or asymmetrical (dynamic); visual weight comes from size, contrast and colour.

Genres include portrait, landscape, still life, fashion, product, documentary and editorial; each has conventions for lighting and lens choice.

Portrait lenses around 85-135 mm (full frame) flatter faces by reducing perspective distortion.

Landscape often uses small apertures, tripods and hyperfocal focus; foreground-midground-background layering adds depth.

Product and still life need controlled lighting, tethered capture and consistent colour reproduction.

Colour harmony: analogous, complementary and triadic schemes create predictable visual relationships.

Cropping and aspect ratio (3:2, 4:5, 1:1) change emphasis; decide crop before final output.

Store lenses and bodies with silica gel in a dry cabinet; humidity above ~60% encourages fungus.

Clean optics with a blower first, then lens tissue and fluid; never dry-wipe grit across the surface.

Batteries: store at partial charge, avoid deep discharge, and never short terminals; lithium cells can ignite if damaged.

Darkroom ventilation must remove chemical vapours; wear gloves and goggles when handling developers and fixers.

Electrical safety: RCD/GFCI protection, no daisy-chained extension leads, keep cables off walkways.

Tripod and stand stability: use sandbags, spread legs, and lock all sections before releasing the camera.

Regular sensor cleaning and firmware updates prevent dust spots and compatibility faults.

Dispose of spent chemistry per local regulations; never pour fixer or bleach into drains.

First aid: flush eyes with water for 15 minutes and seek help; keep a spill kit and eyewash station available.

Estimate jobs by day rate plus usage/licensing; separate creative fee from expenses and post-production.

Written contracts should cover scope, deliverables, deadlines, revisions, copyright licence and payment terms.

Copyright generally belongs to the creator unless assigned in writing; licensing grants specific usage rights.

Model and property releases are needed for commercial use of identifiable people and private property.

Invoicing: state payment terms (e.g. 30 days), late fees, and retain deposits; keep records for tax.

Insurance: public liability and equipment cover protect against location and gear risks.

Ethics: avoid misrepresentation, respect privacy, and disclose manipulated images where context requires.

Portfolio and marketing: consistent branding, targeted genre focus, and client testimonials build credibility.

Pricing should cover overheads, equipment depreciation, insurance and tax, not just time on set.