f/oss
Light meter for photography
Free · Designed for iPad. Not verified for macOS.
A true spot meter for film photographers. Point, read, shoot — free, no subscription.
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.
Ratings & Reviews
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f/oss 2.0 is a complete rewrite — now fully native.
• All-new instrument-deck design
• True spot metering with full-color light analysis — accurate even in LED and neon light
• New Cine mode: shutter angle + frame rate
• New Exposure Value and Manual modes
• Camera profiles: save your cameras and their real limits
• Reference lock: measure scene contrast in stops
• Full/half/third stop increments and configurable ranges
• Faster, lighter — and still completely free
The developer, Luca Tescari, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Luca Tescari
- Size
- 672.8 KB
- Category
- Photo & Video
- Compatibility
Requires iOS 26.0 or later.
- iPhone
Requires iOS 26.0 or later. - iPad
Requires iPadOS 26.0 or later. - Mac
Requires macOS 26.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 tescari.dev