I bought it when I saw it advertized here. It appears to be pretty accurate at low speeds (where it matters to me). I'm not convinced one way or the other about higher speeds since I have nothing to compare against.
I like it. It is a well-built unit. And it's small and very handy, especially if you are shooting LF with older lenses. It now lives permanently in my LF bag along with the light meter and sheet film holders.
Just remember, you do need to get the software separately - it does not come with the unit.
The app works as an acoustic tester, without the optical unit. I'm curious whether the latter makes much of a difference in practice; in theory it's obviously doing more of the Right Thing, but I don't know if it matters really.
I have the acoustic version and have found it useful in that form. It's a little fiddly to zoom in properly on the waveform, and some shutters make enough extra noises that it takes a bit of effort to work out where the "open" and "close" points really are. The latter is where the optical attachment should help, I suppose.
San Diego, CA, USA
The lady of the house has to be a pretty swell sort of person to put up with the annoyance of a photographer.
-The Little Technical Library, _Developing, Printing, And Enlarging_
I just ordered one and it's on its way. The acoustic version is really only good for longer exposures (slower speeds). There is a long thread on the large format forum, which I found encouraging enough.
I have a number of cameras and lenses to try it with, perhaps I'll report the results.
It appears to function just like an optical mic. Since I don't have an iPhone, but do have digital audio workstation software (I can zoom in on a wave form as much as I like and get exact time stamps), does anyone know if this will work when connected to a PC via a 3.5mm extension cable? I've seen a number of home-brew optical shutter speed checkers that work like this, but they are all powered (contain batteries).
I'd love to hear if anyone has tried hooking one of these up to their desktop or laptop through the mic port and tried recording a wave from it.