CALM: Cinema Lighting Matcher

Illuminance and T-stop for 591 fixtures from 44 makers, by distance and accessory. Combine lights, find a stand-in, track the sun and moon, and frame shots on location.

CALM (Cinema Advanced Lighting Matcher) is a lighting calculator for film and video. Pick a fixture, accessory, distance and colour temperature, and CALM gives the illuminance at that point and the T-stop you get with your current camera settings.

It covers 591 fixtures from 44 makers, based on each maker's photometric data: HMI, LED, tungsten, PAR, Fresnel, soft sources and moving lights that crews use every day.

Included with the app

• Calc: illuminance and T-stop from fixture, accessory, distance and colour temperature. A diagram shows the beam angle and coverage; for elliptical beams such as the Joker lenses it gives the diameter and radius of each axis. With DMX charts you can keep on the device for use without a signal, and links to each fixture's page on the maker's site.

• Compare: three lights side by side, with illuminance, T-stop, power draw and weight at the same distance.

• Camera: enter ISO, frame rate, shutter angle and T-stop once, and every calculation follows. Digital, film and stills.

• Manual camera: sets the iPhone to the same exposure as your T-stop, ISO and shutter. Angle of view and frame lines for 40 cameras and 340 lenses, depth of field, Apple Log or Rec.709, 12 looks built on the film process plus LUTs (.cube), retouching, false colour, zebra and waveform. Shots get scene and cut numbers and export to PDF by project.

• Stand-ins: place 3D people in AR and in the manual camera, and pose them.

• Voice control: speak to enter fixtures, distance, colour temperature and more, and move between screens. Speech is recognised on the device only.

• AR measure: measure the distance to your subject with the camera and use it straight away.

• Mired: turn a colour temperature difference into the filter strength you need.

• Colour Match: match a target colour with faders — CCT and ±G, xy, HSI, individual LED emitters, or a crossfade. 5-cue runs, time trials, and reading the xy and CCT of a colour from a photo. Add-ons (one-time in-app purchases)

• MIX: combine several lights for the total illuminance and the mixed colour temperature. Compare up to three setups and save them by name.

• Finder: enter a target T-stop and distance, and see the fixtures that reach it, ranked.

• ALT: find a stand-in for a fixture you could not book, with the number of units needed and a match rate.

• Draft: place people, lights, bounces and camera on a floor plan and read the meter at each angle, with key ratios. Use a PDF or photo as the underlay. Export a shot plan as a PDF too.

• SUN SCOUT: the day's sun and moon paths from any place and date, with sunrise, sunset, magic hour and moon phase, laid over the live camera view. It also gives shadow length and direction, and the fixtures needed to fill shade from your sunlit and shade readings.

• Premium: unlocks all five above.

All add-ons are one-time purchases. There is no subscription.

12 languages: Japanese, English, Spanish, Chinese (Simplified and Traditional), French, German, Portuguese (Brazil and Portugal), Finnish, Korean and Thai.

No account is required. Settings and plans stay on your device and in your own iCloud Drive.

Please note Values are calculated from photometric data. On set, mains voltage, lamp hours, unit-to-unit variation, reflections and the air all change the result, so readings on a real light meter can differ. Use CALM as a guide and confirm with a meter on location.