Fotio is a viewfinder-first light meter for shooting fully mechanical film cameras. You compose through your iPhone, dial in the ISO / shutter / aperture of your film body, and Fotio tells you whether that exposure is over, under, or on target. The phone is only a meter — your film camera’s dials stay virtual and never touch the actual hardware.

Requirements

  • iOS 26 or later
  • iPhone 13 or newer

FAQ

How does the metering work? Fotio reads the scene exposure (EV) from the iPhone’s live, converged auto-exposure — it is not hard-coded. As the light changes, the reading updates in real time.

How do I set the exposure triangle? Drag the ISO, shutter, and aperture dials to match your film body. Lock any dial to hold it fixed; when you change a free dial, Fotio auto-compensates by snapping another to keep the target EV.

Can I meter a specific part of the scene? Tap to take a spot reading. Long-press to reset back to centre-weighted metering.

Why does Fotio need camera access? The live viewfinder and metering rely on the camera feed. That’s the only permission Fotio asks for, and it’s used solely for metering and capturing shots. See the Privacy Policy for details.

Where are my captured shots saved? Shots are saved to an in-app gallery, stored locally on your device. They are not uploaded anywhere and are not written to your system Photos library.

Can I add my own cameras? Yes. The camera library lets you create, edit, and duplicate custom film bodies. Fotio ships with a generic Standard 35mm to start from.

Contact

Questions, bug reports, or feature requests? See the Contact page.