Production: Camera, Lighting and Sound
What the domain tests
Production questions test whether you can expose an image, shape light and capture clean sound on set. Expect numerical reasoning on exposure, lighting ratios and audio levels, plus terminology on lenses, microphones and movement.
Core rules and concepts
- Exposure triangle: aperture (f-stop, halving light each stop), shutter and ISO. The 180-degree rule sets shutter to 1/(2 × frame rate), e.g. 1/50 s at 25 fps for natural motion blur.
- Lens and sensor: focal length controls field of view; wide lenses exaggerate depth, long lenses compress it. White balance matches light colour temperature - about 3200 K tungsten, 5600 K daylight.
- Lighting: three-point setup of key, fill and back light. A 2:1 ratio means the key side is twice the fill side. Intensity follows the inverse-square law, so doubling distance quarters the light.
- Sound: dynamic mics are rugged; condenser mics are sensitive. Polar patterns include cardioid, omnidirectional and hypercardioid. Record at 48 kHz/24-bit, peak around −6 dBFS, and capture 30 seconds of room tone.
Worked example
A key light gives 800 lux on the subject; the fill gives 400 lux. Reasoning: 800 ÷ 400 = 2, so the key-to-fill ratio is 2:1, a gentle contrast suitable for a dialogue scene. If the director wants 4:1, either double the key or halve the fill using diffusion or a dimmer. Note that moving the fill twice as far away reduces it to one quarter, overshooting the target.
Traps that cost marks
- Confusing shutter angle with frame rate; 1/50 s is not a frame rate.
- Leaving auto white balance on when mixing tungsten practicals and daylight.
- Choosing an omnidirectional mic for a noisy outdoor interview.
- Forgetting room tone, which makes dialogue edits sound abruptly silent.