f/oss

f/oss is a free light meter for film photography — rebuilt from the ground up as a fully native app. Point the spot-metering circle at your subject and read the exposure instantly. f/oss measures true photometric luminance through your iPhone's camera and is calibrated against professional reference meters. FIVE METERING MODES • Aperture Priority — set f-stop and ISO, get your shutter speed • Shutter Priority — set shutter and ISO, get your f-stop • Exposure Value — read the scene's EV directly • Cine — shutter angle and frame rate for filmmakers • Manual — check your chosen settings against the metered scene BUILT FOR REAL CAMERAS • Camera profiles: save your bodies with their actual shutter and bias limits • Full, half or third stop increments • Configurable shutter, aperture, ISO and exposure bias ranges • Reference lock: freeze a reading and measure scene contrast in stops • Exposure lock for recompose workflows ACCURATE • True spot metering of exactly the circle you see • Full-color light analysis — reads saturated LED and neon light correctly • Verified against professional meters from daylight to low light FREE, NO SUBSCRIPTION Every feature is free, forever. If f/oss saves your shots, there's an optional tip jar — that's it.