ShutterDoc

Support

A question, a problem, or a reading that looks wrong: write to hello@shutterdoc.app and one of us will reply.

Start with the app's own guide

The home screen has How to set up a test, which walks through setting up a camera step by step, and Common questions, which covers how the measurement works and what the results mean.

What you need

• An iPhone that films slow motion. The top of the home screen shows the frame rate your phone will film at. ShutterDoc is built for 240 frames a second; at a lower rate the fast speeds are measured less precisely.
• A film camera with no film in it, and its back open.
• A bright, even light that does not flicker: a white wall, a window on an overcast day, or a sheet of paper over a lamp. LED and fluorescent lights flicker too fast for you to see but not too fast for the phone.

If a reading looks wrong

Most surprising readings come from the setup rather than the camera: a light that flickers, part of the shutter outside the picture, or the phone, camera or light moving partway through a test. The app says when it doubts a reading, and usually why.

If you still think something is off, write to us with the camera's make and model, the speeds you tested, and what the app reported. A screenshot of the results helps.

Your data

ShutterDoc keeps everything on your phone and sends nothing to us. The privacy policy has the details, including how to delete what the app stores.