ShutterDoc: Shutter Speed Test

Measure what your film camera's shutter is actually doing. ShutterDoc measures shutter speeds in ordinary room light, handheld up to 1/60.

Take the lens off, open the back, point the phone into the mount and fire. A run from 1/30 to 1/500 on an SLR, three firings a speed, takes about two minutes. A test roll costs you the film, the developing and a fortnight of waiting, and still leaves you guessing which speed was off.

You can also detect shutter capping for speeds up to 1/1000th of a second.

WHAT IT DOES

Measures speeds from 1 second to 1/500, on focal-plane shutters, so most SLRs and rangefinders, and on leaf shutters, so folders, TLRs and fixed-lens compacts. Separate guidance for each.

Detects shutter capping. It maps the exposure across the whole film gate and finds bands that received little or no light, on horizontal and vertical shutters alike.

Puts a confidence on every reading, and says when conditions will not support a number you can trust.

Keeps a library of your cameras, with shutter type, flash sync and notes, tested or not, and saves every session so a body can be compared over time.

Exports readings and capping maps as CSV, for a repairer or a buyer.

Walks you through the setup the first time you open it.

WHAT IT IS FOR

Buying. The seller says the speeds sound about right. Check before the money changes hands, at a flea market or across a cafe table.

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