Quote Originally Posted by pchaplo View Post
Good points about consistency and testing. Which shutter speed tester do you use? I see there is even a phone app!
I use this one, $15 at ebay:

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It is a bare photocell intended to be connected to PC soundcard, but I connect it to an USB oscilloscope.

There are photocell versions wired to be compatible with smartphones jack sockets, and there are $1 apps for it that also can work with shutter's noise, but with noise it is not accurate and has limitations.

This standalone one is around $75 :

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