A quick way to test your shutter speeds
After seeing many ads over time saying 'the slower speeds may be off' I thought I should share a simple trick I use for examining shutter speed problems.
Download a small and free audio recording program like Audacity or Reaper and use a computer mic to record the shutter. For at least the slow speeds you should be able to zoom in and see how long the shutter opens and closes, with the buzzing in between.
I don't know how many other people do this but it works for me. Not super accurate but better than 'eyeballing'/listening for it.
Yes, I did the same last year for my LF lenses and was rather suprised that the older Compur lenses were the most accurate.
And it's probably almost as accurate as many of the other methods.
There's a thread on the LargeFormat forum about this that has got quite... involved :o
But basically... you can plug a simple phototransistor into your sound card and use Audacity to measure the shutter speed that way, too. It's accuracy is limited to about 1/200s at best - after that it can't measure shutters very accurately at all. Neither is it very good with focal plane shutters.
Unless... you add just a little more electronics and place a pinhole over your phototransistor. It can then reasonably good for up to 1/1000s (and as slow as you like) even on focalplane shutters (well... big ones )
Beauty my Ilex #3 in slow by a stop.....but one copal is good, have to check the other one now. I was going to build (and I still might) the simple
phototransistor one here (http://www.rusted.free.fr/speed%20tester.html)
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The easiest way for me is simply to put in a roll of Velvia and to go through all the speeds at the same EV. If all slides are exposed consistently everything is fine for me. Velvia does show even minute variations in exposure if you have a close look at the slides. I must admit that I do not have many cameras or leaf shutter lenses. Otherwise this would be a method too expensive for sure...
Good tip, thanks for sharing, I already have Audacity installed, but never thought of this.
Originally Posted by Krzys
"The nineteenth century began by believing that what was reasonable was true, and it wound up by believing that what it saw a photograph of, was true.
" - William M. Ivins Jr.
"I don't know, maybe we should disinvent color, and we could just shoot Black & White.
" - David Burnett in 1978
"Analog is chemistry + physics, digital is physics + math, which ones did you like most?
Another way to do a shutter speed test involves the use of a D***l camera. You will have to place the lens/camera to be tested front to front with the d****l camera (like if they were kissing) You may use just black tape to avoid light leaks or use a combination of adapters and reverse mount adapters.
The area on the back of the lens/camera to be tested should be lit by a constant and even light source
This method assumes that a recent or new d***l camera with an electronic controlled shutter will be accurate
Here is the procedure:
The lens in the d**l camera should be on manual, constant aperture, constant ISO
- First put the lens to be tested open and make an exposure with the d***l camera at the speed or speeds you want to test
- Look at the histogram, you should see a narrow band at some point. You can adjust where the band should be either with ISO or the d****l camera lens aperture
- Now, cock the shutter to be tested and open the shutter in the d****l camera on B. Release the shutter to be tested
- Check the histogram and compare with the previous histogram. You would be able to tell if the shutter is accurate or how much it is off.
- You can also use this procedure to check the effect of high shutter speeds whit small apertures in central shutter or to check if the diaphragm is properly closing before the shutter.
Thanks for information, very useful!
This is a great way to test shutter speeds. Just a note though, Reaper isn't free except for evaluation. It's an amazing audio recording platform so if you decide to keep it and/or use it for recording, please support Justin and buy a personal license.
Thanks and regards,