About this app
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 is an optional tip jar.
Latest release
What’s New
• Added an optional tip jar and an in-app FAQ • Smoother metering readout with animated digits • Steadier stop selection with less flicker in the reading • Fixes and refinements throughout
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Aug 20, 2026 · 1:28 AM Free
Screenshots
