Plan illuminance by task and scene rather than applying ordinary residential lighting assumptions.
Design by task, not one target
Arrival, pause, cleaning and film scenes have different jobs. Step guidance may need only enough luminance to reveal an edge, while cleaning requires broad, honest illumination. Combining them into one average lux target produces a compromised room.
Surface brightness matters
A small bright aperture can cause more distraction than a larger softly illuminated surface delivering similar useful light. Consider where the eye sees the source, the contrast against its surroundings and how pale materials may reflect light toward the screen.
Commission from the seats
Meters provide repeatable data, but scene judgement remains experiential. Sit in every row, allow time for adaptation and assess movement paths, faces, controls and screen contamination. Store the final values only after the real room has been tested.
Good cinema lighting gives the room exactly enough information—and no more.
A practical specification sequence
Define the visual intent and the scene in which the light will operate. Confirm the fitting, driver, control method, circuit and physical access together. Build a representative mock-up where the detail is sensitive, then commission the final level from every seating position with the projection system running.