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 is an optional tip jar.