Zone Light Meter

Zone Light Meter is a light meter for people who shoot film. Point your phone at the scene, read it the way a handheld spot meter would, and get an aperture and shutter speed your camera can actually set. It is built around the Zone System, but you don't need to know the Zone System to use it. METERING • Reflected metering through the rear camera, including the ultra-wide lens • Single spot with pinch-to-zoom, multi-spot averaging (3 to 9 readings) and Auto Zones • Hold a reading, then change aperture or shutter without losing it • Aperture and shutter priority, f/0.95 to f/64, 1/8000 to multi-minute exposures • Full, half and third stops, plus the old German continental aperture scale • Bulb timer that starts by itself when the phone is held steady THE ZONE SYSTEM, MADE VISIBLE • Zone scale ruler for your spots and a subject brightness range readout • False-color overlay, live histogram and blinking warnings for lost shadows or highlights • Protect shadows or protect highlights with one tap • Development advice (N+1, N-1) from the contrast you measured FILM AND CORRECTIONS • 674 film stocks with box speed, push and pull • Reciprocity failure for each stock, with a warning when a long exposure crosses into it • Filter factors, bellows extension, expired film, multiple exposure, infrared and pinhole • Bracketing assistant and an exposure ladder of every valid combination YOUR GEAR Pick from about 1,230 lenses and 692 camera bodies, or add your own, and star the ones you own. The meter only offers apertures and shutter speeds your camera has, warns about flash sync, and keeps whole setups as presets you can switch with a swipe. SHOT LOG Log each frame with its exposure, film, lens, location and a reference photo. Group shots into rolls, add development notes and export everything to CSV. MORE TOOLS • Sun and moon times with golden hour, blue hour and alarms • Viewfinder compass with true north and the sun's bearing • Darkroom enlarger timer with test strips, dodging and burning, and multigrade filters • Alternative processes: cyanotype, platinum/palladium, salt print, Van Dyke and more • Cine mode: frame rates, shutter angle and footage runtime • Flash guide number, depth of field, large format movements, bubble level and a whiteboard light MADE FOR THE FIELD Dark, Paper and strict red-light themes, volume buttons as a shutter release, a maximum brightness mode for sunny days, and a calibration step that checks your phone against a gray card or Sunny 16. PRIVATE AND OFFLINE Metering, the catalogues, sun and moon times and the shot log all work with no connection. Place names and the shot map come from Apple Maps when you're online. No account, no ads, no tracking. Your rolls, gear and settings stay on your phone. Built and maintained by one developer. Questions and ideas: hello@zonelightmeter.com