How a Lighting Plot Goes From Blank Floor Plan to Rigged Studio

It starts with the room, not the lamps

Before anyone draws a fixture, we go and stand in the space. A lighting plot is only as good as the measurements behind it, and the plans we are sent are often a few years out of date. We walk the floor with a tape and a laser measure, note the ceiling height at several points, and look for the things that never appear on a drawing: a sprinkler head hanging lower than the grid, a beam that cuts across a planned throw, a door that swings into the working area.

We also ask what the room is used for on an ordinary week. A studio that records a daily programme has different needs from a hall that is dressed for a conference twice a month. That conversation decides whether we recommend a fixed grid, a motorised hoist system or a simple set of floor stands, and it saves arguments later.

Photographs taken from the camera positions are the last job of the visit. They give us the real sightlines that the lighting has to respect.

• Ceiling height at several points, not one
• Grid or truss loading limits from the building owner
• Power supply and distribution board locations
• Sprinkler heads, vents and fixed obstructions

Drawing the first plot

Back in Bath, Priya or I draw the first plot in a drafting package, working from the measured floor plan. We place the set pieces first, then the camera positions, and only then the fixtures. Lighting follows what the cameras need to see, so starting with lamps and hoping the shots fit is the wrong way round.

The first draft is deliberately plain. It shows key, fill and back light for each playing area, a general wash for the background, and a note of every fixture type with its approximate throw distance. We keep it to one sheet so the client can mark it up with a pen without needing the software.

Most clients change something at this stage, usually where a presenter will actually stand compared with where they said they would. We would rather hear that now than on the rigging day.

Checking the numbers

Once the layout looks right, we turn it into figures. Each fixture has a wattage, and each circuit has a limit. We total the load per dimmer channel and per distribution outlet, then compare it with what the building can supply. It is dull work, but it is where plots most often fail in practice.

We also check weight. A grid or a length of truss has a safe working load, and fixtures, cables, barn doors and safety bonds all add to it. Where the building owner has not given us a figure, we say so in writing and ask for one rather than guessing.

Heat is the third check. Tungsten fixtures in a low studio warm the room quickly, so we note where LED units would reduce the load on the air handling, and give the client the trade-offs in plain terms.

• Load per dimmer channel and per outlet
• Total weight on each grid bar or truss section
• Heat output against the room's ventilation

Colour, camera and the gallery's view

A plot that looks good in the room can still look wrong on the vision mixer. Before the rig is finalised, we talk to whoever will be shading the cameras, because the lighting has to give them something workable. Skin tones, white balance and the contrast between a bright set and a darker surround all affect how much correction the gallery has to apply live.

Daniel and I usually compare notes at this point, since camera settings and fixture choices pull against each other. A fixture with a slightly different colour output can make a camera operator's job easier or harder for the whole run of a series.

If there is time before the rigging day, we ask for a test frame from the actual cameras with a handful of fixtures lit.

The rigging day

On the day, the plot becomes a work list. We number every fixture on the drawing, label it to match, and give the crew a sheet showing the order of work: grid first, then power, then fixtures, then cabling, then focusing. Working in that order avoids climbing the same ladder three times.

We stay on site for the focusing, since that is where the design meets the room. Fixtures are pointed and shuttered while a stand-in walks the playing areas, and small changes are made until the faces and the background sit properly against each other. Some of the best adjustments come from a gaffer saying that something looks odd.

Everything that moves from the drawing is marked in red, so the final plot reflects what was installed rather than what was planned.

• Numbered fixtures matched to the drawing
• Work order set out for the whole crew
• Focusing done with a stand-in on the set
• Red-pen record of every change on the day

What the client keeps afterwards

When the rig is finished, the client receives the corrected plot, a fixture schedule and a simple note on how to strike and re-rig the set if it is moved. We find the schedule gets used most, because it tells a new technician what each lamp is and where it belongs.

We also leave a short list of things to watch: lamps that are near the end of their life, cables with worn sleeving, any area where the lighting was a compromise. It is honest and brief, and it means the next problem is found by the client before it reaches air.

If something looks wrong after the first few recordings, they can send us a message through the contact page and we will go through it with them.

A lighting plot is the result of a series of ordinary steps done in the right order: measure the room, draw from the camera outwards, check the load, test the look and keep a clean record. None of it is complicated, but skipping any stage tends to show up on the rigging day or on screen. That is why we spend more of our time on the plan than on the lamps.