A working limit of three hues in a look, each with a different job. Coverage maths, channel budgets, circuit arithmetic and a full worked palette for a 6 m stage.

Additive mixing explained, why RGB-only fixtures produce a greyish white, and when the extra white emitter is worth paying for.

Rolling bands, strobing in slow motion and colour shift on camera. What causes LED flicker and how to fix it before the shoot, not in post.

Doubling distance quarters the light. The rule that explains why front truss height, stage depth and riser positions matter more than fixture choice.

Watt is a power draw, not a brightness. The three efficiency numbers that actually predict how much light a fixture puts on stage, and how to plan a circuit without guessing.

Beam angle sets the throw, field angle sets the spill. Together they decide coverage, fixture count and whether your stage has dark gaps.

What each unit measures, how to convert between them, and why the lumen figure on the box tells you almost nothing about how bright a fixture looks on stage.

The two digits, the tests behind them, and why an IP-rated fixture still needs a plan for rain, condensation and the cable entry.

CRI, colour temperature and the white-point problem behind mismatched whites, skin tones that go grey and footage that never matches the room.