What a Lighting Plot Is and How It Gets Used in the Studio

What the term actually means

A lighting plot is a scaled plan of the studio seen from above, showing where each lamp hangs, what type it is, which way it points and which circuit or dimmer feeds it. It is the document the lighting team builds a show from, and it is the one the floor manager glances at when someone asks why a lamp is missing from the grid.

People new to the gallery sometimes confuse the plot with the lighting design itself. The design is the idea: warm key light on the presenter, a cool wash on the backdrop, a pool of light for the interview sofa. The plot is how that idea is written down so that a rigger can build it without asking the designer a dozen questions.

In a working studio the plot is rarely a single sheet. There is usually a base plot for the permanent grid and a show plot laid over it, with changes marked clearly so nobody mistakes one for the other.

What goes on the drawing

Each lamp on the plot carries a short label. That label normally gives its position on the grid, the type of fixture, its channel number and any colour filter or accessory fitted to it. Beside the symbols there is a key, so a new member of the crew can read the plot without a briefing.

Alongside the plan sits the schedule, a table listing every fixture in order. Where the drawing shows location, the schedule shows detail: lamp wattage, cable length, barn doors, diffusion. When the two disagree, the crew has a problem on its hands, which is why they are best produced and updated together.

Good plots also record what is not lit. A note that the cyclorama wash is switched off for the bulletin, or that a practical lamp on the desk is dimmed from the gallery, saves a surprising number of phone calls during a recording.

• Fixture type, position and channel number
• Colour filters, gobos and accessories
• Circuit or dimmer assignment
• Notes on anything controlled from outside the lighting desk

Who reads it and when

The lighting director reads the plot first, checking the design against the set and the camera plan. Riggers read it next, working from the schedule to hang and cable each fixture in a sensible order. The gallery operator reads it last, using the channel numbers to find the lamps they will be raising and lowering live.

Camera operators and directors read it too, though they would rarely say so. A shot that looks into a cluster of lamps, or a presenter who walks into a shadow, is usually visible on the plot before it is visible on the monitor.

For that reason the plot belongs in a shared place rather than in one person's folder. When producers, the floor manager and the technical crew all see the same current version, questions about what is hanging where are settled in a minute rather than in a corridor conversation.

Rig changes between bulletins and shows

The real test of a plot comes when the studio changes character. A newsroom set in the morning may become a game show set by the afternoon, and the grid has to follow. A rig change is the list of moves, additions and removals that takes the studio from one plot to the next.

Written well, a rig change reads like a short set of instructions: lower bar three, swap two profile lamps for soft sources, refocus the backlight on the new desk, restore the cyclorama circuits. Each step can be given to a different person and checked off, so the whole team does not stand around waiting for one voice.

The most useful habit is to record the change against both plots. Then the studio can return to the earlier look the next morning without relying on someone's memory of where the lamps were pointing.

• Name the plot you are leaving and the one you are moving to
• List removals before additions
• Mark every refocus, not only the lamps that move
• Note anything that must be tested before the studio is handed back

Common ways plots go out of date

Plots rarely fail through one big mistake. They drift. A lamp is swapped because a bulb blew, a circuit is borrowed for a monitor, a bar is lowered an extra half metre for a camera crane, and nobody updates the drawing because the show is about to start.

After a few weeks the plot describes a studio that no longer exists. The next designer trusts it, the riggers build from it, and the discrepancy only appears when the lights come on and something is wrong.

The cure is dull but effective: treat the plot as a record of what is in the studio now, and make updating it part of closing a rig change, not an optional extra. When the person who made the change also marks the drawing, errors stay small and findable.

Keeping the plot useful

A plot is only as helpful as it is readable. Keep symbols consistent from one show to the next, so the crew does not have to relearn the drawing each time. Use the same channel numbering where you can, and when you cannot, say why on the sheet.

Give every version a clear name and a simple note of what changed since the last one. A crew member who finds two files with similar names and no explanation will, sooner or later, build from the wrong one.

Finally, remember who the plot is for. It is a working tool for people standing on a ladder, often in a hurry. If a detail will not help someone hang, focus or operate a lamp, it probably belongs elsewhere.