Camera light meter

No meter on your old camera? This reads the brightness through your device camera and suggests an exposure. It is approximate — calibrate it once against a scene you know, then trust the relative readings.

Phones auto-adjust their own exposure, so absolute values drift — this is a backup and learning aid, not a substitute for a proper meter. Point at a mid-tone (like a grey card) for the most consistent reading. The camera feed never leaves your device.

About this tool

This tool uses your device camera as a rough light meter. It reads the average brightness of the scene, estimates an exposure value and suggests a shutter speed for your film ISO and aperture. It is approximate, so you calibrate it once against a scene whose exposure you know.

How to use it

  1. Press Start camera and allow camera access.
  2. Enter your film ISO and the aperture you plan to use.
  3. Point at a mid-tone and read the suggested shutter speed.
  4. To calibrate, enter the true EV of a known scene and press Set calibration.

FAQ

Is it as accurate as a real meter?

No. Phones auto-adjust their own exposure so absolute values drift; treat it as a backup or learning aid and calibrate against a known meter.

Does the camera feed leave my device?

No. The video is processed only in your browser and is never uploaded or recorded.