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Favorite Classics Camera & Repair Articles Test Equipment Shutter Speed Tester
The easiest way to get a shutter speed tester is just to buy one. Micro-Tools has excellent ones from Delta and ZTS but they are kind of pricey for the hobbyist. I even think the Calumet tester is pricey. I bought my Delta SHT-1 used. Otherwise I’d still be using my homemade one. What can I say, I’m a tight wad. If you’d like to make one, it is not very hard to do.

If you have a digital multimeter already, you can make a shutter speed tester easily and cheaply. It’ll be more work calibrating and using than the "store bought" unit. But the price is better. The multimeter must have high enough impedance not to bleed off the capacitor.

Theory: A capacitor stores voltage. The magnitude and duration of the voltage applied determines amount stored. For a set aperture and light level (magnitude), then the faster the shutter speed (duration) the less voltage is stored.

Gather up all the components listed on the circuit drawing and assemble as shown in the pictures. This is just my own personal physical arrangement, nothing sacred. Feel free to modify it anyway you desire. The power source voltage, resistor value and capacitor rating are all variables also. The values shown are from Tomosy’s first book. Different values will change the range of the shutter speed readings. You should seriously consider purchasing Tomosy’s and Romney’s books. They are a good read. I’ve seen this same circuit with different value components in basic electronic experiment books.

I use 3/16" thick light baffle material on the tester surface that contacts the cameras focal plane. All extraneous light must be blocked.

Use the Adjustable Light Source set at a known EV and at a standard distance from the camera. The light brightness and distance from camera must not vary. Calibrate by recording the voltage readings of a known accurate shutter at all its speeds. Better yet, compile data from several known accurate shutters to be even mor accurate.

My standard setup is to set the Adjustable Light to EV 13, for camera at a focal plane distance of 8" with lens installed and aperture set at 3.5, room lights off .

Tomosy also shows how to turn a Commodore 64 into a shutter tester, but I haven’t tried this... yet. What I am working on is using my laptop and a parallel port adapter to do apertures, shutter speeds, curtain speeds and EV’s. I’m not very good at programing so this may take awhile.