ShuttR: Shutter Speed Tester

Is your vintage camera's shutter still accurate — or has it drifted after decades of use?

ShuttR Check measures the real shutter speeds of your analog camera using nothing but your phone's camera and a light source. No hardware testers, no sensors to buy, no guesswork — reliably from 8s down to 1/500, with experimental fast times up to 1/2000.

REQUIRES 240 FPS SLOW MOTION
ShuttR Check times the shutter at 240 frames per second. Your phone's main camera must support 240 fps slow motion through Android's camera API, and the phone must process it in real time. Not every phone that films slow motion qualifies: some manufacturers keep 240 fps to their own camera app. ShuttR Check checks your phone on first launch and again while measuring, and tells you clearly if it can't — no inaccurate readings. If your phone isn't supported, you can get a refund through Google Play. Tested on: Google Pixel 8a.

HOW IT WORKS
Open your camera's film back, remove the lens, and put a light source behind it. ShuttR Check uses your phone's high-speed camera to measure exactly how long each shutter release lets light through, then tells you how far that is from the speed you dialled in — in fractions of a stop.

The app walks you through every step. There is nothing to configure, nothing to interpret: set up, release the shutter, read the result.

RELIABLE FROM 8s TO 1/500 — FAST TIMES UP TO 1/2000
ShuttR Check measures dependably from 8 seconds down to 1/500 — the range where mechanical shutters drift the most and where a deviation actually shows up in your negatives. 1/1000 and 1/2000 are available as experimental fast times: they're measured with the same method and shown with their deviation, but because they're less precise, they don't count towards your camera's overall verdict. We'd rather be clear about that than hand you numbers that look more precise than they are.

WHAT YOU GET
• A guided, step-by-step measurement protocol — no technical background needed
• Automatic calibration (checks your room is dark enough and free of flickering light)
• Every speed compared against its nominal value, with the deviation in stops and a clear OK / deviation / defective verdict
• A history per camera and a service log, so you can track a shutter's condition over time
• A shareable "shutter checked" certificate (image or PDF) — perfect for camera sellers, showing buyers exactly what they're getting
• Backup export compatible with ShuttR Check on iPhone

SHUTTER TYPES
Horizontal and vertical focal-plane shutters are tested and validated — the shutters in most classic SLRs and rangefinders. Leaf (central) shutters should work just as well, since the app measures the light pulse itself, but they haven't been through the same validation, so treat those readings as unconfirmed.

WHAT THIS APP IS NOT
ShuttR Check gives you dependable, repeatable information about how far your shutter speeds have drifted. It does not replace a calibrated measuring instrument, and the results are not a laboratory reference.

It also does not measure shutter capping. The app times how long light passes through, not how evenly the curtains expose across the frame.

PRIVATE BY DESIGN
No account. No data collection. No internet connection required. Everything — your cameras, your measurements — stays on your device.

WHO IT'S FOR
• Film photographers who want to know if their gear is actually accurate
• Camera collectors curious about a new find
• Sellers who want to offer buyers real proof of a working shutter