# The Photoplug shutter speed tester



## Compaq (Mar 16, 2015)

The Photoplug (optical mini-jack addition to smartphone for shutter speed tests) came in the mail today, and I have been testing the shutter speeds of some rangefinders of mine. This is extremely useful. I have been suspecting that something is up with the shutter speeds, and now I have strong evidence that I was correct!

On both my Olympus 35 SP's, apparently the 1/500s is closer to 1/240s, giving me an overexposed image by about a stop. The theoretical 1/250s is more like 1/200s, giving a slight overexposure. The slower shutter speeds are very accurate, it seems. Actually knowing this is great. I can make tiny notes and tape them to the cameras, and stop overexposing my films.

Anyway, if you need to check the shutter speeds of your camera, and didn't know that this existed, you should definitely check it out here: PhotoPlug

Anders


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## tirediron (Mar 16, 2015)

Interesting...  seems quite reasonably priced, assuming that it, itself is accurate.


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## 480sparky (Mar 16, 2015)

I'm fortunate to have an old optical device... Northeast Instruments.  Made back in the 70's


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## Compaq (Mar 16, 2015)

tirediron said:


> Interesting...  seems quite reasonably priced, assuming that it, itself is accurate.



I have requested some kind of technical documentation from the seller, but I don't know if he will provide them to me. I plan to check the accuracy by testing a "reference camera". It's just that all I have is a 15 years old Canon EOS 300. The negs it produces seem correctly exposed, but if the test is supposed to be a good one I should probably use a newer camera.
I wondered if I could use my DSLR by doing an optical measurement through the viewfinder, but the measurements were way off.

The following video compares the sound-based measurements with something that looks like proper set-up.


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## 480sparky (Mar 16, 2015)

Compaq said:


> .......I wondered if I could use my DSLR by doing an optical measurement through the viewfinder, but the measurements were way off......



I doubt it.  All you would time is the mirror moving up and down.


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## tirediron (Mar 16, 2015)

480sparky said:


> Compaq said:
> 
> 
> > .......I wondered if I could use my DSLR by doing an optical measurement through the viewfinder, but the measurements were way off......
> ...


You could just drill a 1/2" or so hole in the middle of the back of the DSLR; as long as you don't go too deep and hit the shutter it should work.


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## 480sparky (Mar 16, 2015)

tirediron said:


> 480sparky said:
> 
> 
> > Compaq said:
> ...



Or you could do it like I do.


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