Homemade Shutter Speed Tester With A Mic

Home Made Shutter speed Tester Using A Mic and a computer.

I am aware that there are slightly more sophisticated methods available to test your shutter, with a couple simple parts that you can get from Radio Shack, even. But this will cover the most basic one, using a computer, a mic, and some audio editing software such as Audacity. It will work much better for slower shutter speeds, such as 1/60 and below and it is pretty accurate. Basically what we are doing is recording the sound of your shutter and analyzing it.

In this tutorial:
Rolleiflex T with a Synchro-Compur Shutter ( set to 1 second )
A Mic
Audacity

If you are familiar with using audio editing programs, simply place the mic as close to the shutter as you can* (* it will work better if you use a cable release and mirror lock-up so you don’t record any other unnecessary sounds) press record, and trigger the shutter. You will see something like this:

Now that you have figured out what all the spikes are, you can crop out unnecessary sections. And I remind you, the spike that says “Shutter Opens” in the above photo can be misleading. The shutter is only fully open towards the end of the spikes because the spike will include the noise from the releasing mechanism, and that’s where we start counting. Now, lets look at this again:

The highlighted area should be just about when the shutter is fully opened and closed. If you read the time up there, it is pretty close (or rather, exactly) to 1 second. This 50 year old shutter still performs flawlessly. At 1 Second.
If you don’t believe me, now I’ll put Mamiya 645 PRO to the test. I’ll set it at 1/30 of a second with Mirror Lock Up, since that will be easier to record.

Since its 1/30, and 1/30 = 0.03333333333…    , Read the time stamp above. Pretty close again!

I know this method is not precise, but it will get you somewhere determining how your shutter performs in general, especially in slower speeds. You will have to figure out which spike in the graph represents the shutter opening and closing.  I figure its more confusing if you do not have MLU, but, you can figure that one out.

EDIT

Alright I have a little time on my hand. Here is one for a K1000 without MLU at 1/30, which is pretty much right on the mark again.

I also did a test on 1/500 1/250 and 1/125 via a Petri 7S for the hell of it. It is somewhat hard to read if you’re not familiar with these. It did give me a ball park result on the above shutter speed, they are all different and they are progressive. Amusingly,  they are somewhere around the 0.002, 0.004 and 0.008 mark respectively. But they are too vague for me to consider them as actual data.  But the bottom line is, at least they are progressively different, so in a sense, they work.

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