Does anyone know the best way to test the shutter speed on a camera lens meant for a graphlex?
Does anyone know the best way to test the shutter speed on a camera lens meant for a graphlex?
Huh? Graphic press camera or Graflex SLR?
If you don’t have a shutter tester then either shoot some narrow latitude film or have a CLA at a repair shop. It sounds old enough for a CLA anyway.
For any shutter, especially a leaf shutter, there are DIY shutter testers. I made one that uses pulsed light at 10,000 Hz from an LED that goes through the lens and hits a photo-transistor that converts the light to voltage signal. A sound card on a laptop with Audacity (free) reads the voltage signal. I then measure the open-close signal time to get shutter speeds. It takes about 30 minutes to do three-measures per shutter speed and figure out the average speeds and the ranges. Here is the link to the plans:Originally Posted by Andy F
http://www.hrtranslations.com/photo/.../shutter2.html
I used a box that 35-mm slides came in for the electronics housing, and a 35-mm film can and small wooden board to hold the photo transistor against the film rails or lens. USB voltage can run it, but I found it noisy so I use a 9V battery.
The accuracy is about 1/5000 second (half the frequency of 10K, using the Nyquist interval). I could have gone to 20,000 Hz, with 1/10,000 accuracy, but none of my shutters are faster than 1/2000, so the audio files are smaller with a smaller sampling rate.
If the lens is for a Graflex,it doesn't need a shutter. Use the one built into the camera.
Microphone + audacity, measure the time between clicks. It won't be hyper-accurate, but should give you an idea if you're in the right neighborhood.
Use a shutter speed tester and then write the actual speeds on a piece of paper and tape it to the lens board. If the speeds are too far off then get it CLA'd.
There is an iPhone app that works well enough for b&w. Actually it works great and consistently by measuring and displaying the sound wave of the shutter. But interpreting the results may lead to errors if you were to use it for accurate exposures with transparencies. There is also an adapter available for a small price that measures the duration of light passing through the shutter which makes it more precise. It's called Shutter-Speed.
https://apps.apple.com/us/app/shutter-speed/id560154244
What is a CLA'd
Clean, lubricate and adjustment.
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