Classic camera-shutter testing

Does the shutter works accurate?

Check the shutter-speed electronically.

Here's how to check the speed of the shutter from your classic camera.

If you want to use your classic camera and would like to know whether the speed of the shutter is reliable or not.

You can check that very easily.

1) To do this you’ll need the free program "Audacity" or any other sound program.

2) Cut off your microphone from the microphone-wire connected to your computer.

3) Connect the phototransistor i.e. BPW40 to the wire.

4) Take a piece of board (6 x 20 cm) drill a hole in it, just big enough to hold the phototransistor and mount the phototransistor into that hole.

5) Cover the board with black velvet or leather or anything else as far as it is black. (leave the opening for the phototransistor free).

6) Place the shutter or camera with open film back strait above the phototransistor and a strong light above the camera lens. 
Not too close to cause too much heat  of the lens on the lens surface. 20 cm would do.



Selected Shutter speed 1/1 second for testing purposes.

Place the camera with open film back or just the lens right above the led opening.
Switch on the light above the lens.

Start the Audacity program and hit the red recording knob.


You'll see the recording location stripes running on the screen.  Fire the shutter and then stop the recording by pressing the orange knob.

Now press I on the upper screen rule next to the red button.
Cover the exposed time graphic between the two peaks.
In the window below you'll see the exposure time in milliseconds.
In this case 0,999 seconds which means an almost 100 percent correct result of an 80 years old Plaubel Compur shutter.



I'm sure you wonder how they tested the shutter speed back in the beginning of the last century without having computers and electronic devices.

The next page will give you a clear answer to that including a photo of the mechanical shutter tester.

Mechanical Shutter Tester

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