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Shutter Speed Calibrating
Hi, I have acquired a Linhof monorail and as I am very much a new boy on the Large Format scene I hope my questions are not too naive.
Do you guys have some simple, accurate way of testing shutter speeds ?
To those of you who are kind to answer Thank You.
Rob Hale
My experience is that Copal shutters from the past two or three decades are almost always accurate. Depending on what types of shutters that you have, and how old they are, you might not need to test them. If you have recent shutters and your exposures come out fine, my advice is not to worry about it.
With experience, one can usually judge by sound whether a shutter is getting out of adjustment. If you have several shutters, try comparing them by ear. With between-the-lens shutters, the slow speeds are the ones most likely to have a problem, becoming too slow as the lubrication gums up. This is common in shutters older than about 1970.
The US/UK/Netherlands retailer Calumet (http://www.calumetphoto.com) sells an inexpensive shutter speed measuring device that is popular. In the US, some camera repair places will measure shutter speeds for free (hoping that they find a problem that you will pay them to fix). Even if a repair service charges a small fee, unless you have many lenses it might be cheaper than buying your own measuring device.
There's an interesting article here: http://www.skgrimes.com/idcc/. If you'd rather test your shutters quickly and get on with making photographs, buy a Calumet shutter tester for about $100.00. The instructions are very thorough and give you what you need to know to determine how much to adjust your aperture for a shutter which is off the mark, but consistent.
Regards,
Will
I can't recall where I got this a few years back but there is likely some useful information included for using TV scan rates, etc to check out shutters.
http://www.chibardun.net/~craigclu/shutterTV-1.doc
My feeling always was - perhaps it is naive - that with B&W negative film, a slow shutter wasn't much of a problem, unless it got really and noticeably slow. Who cares if my film is 1/2 stop overexposed? This is well within the latitude of the film and it will print just as well - and perhaps even better. And, when you get familiar with tour equipement, this overexposure is going to be factored in your processing time, etc, getting invisible over time.
If you shoot transparency film, however, you'll want more fine control and a well adjusted shutter will be critical.
Depending on the type of shutter, if you happen to have some digital sound recording software that can show you the waveform of a sound file, you can record the sound and often determine the time that the shutter is fully open by looking at the waveform. There should be distinct peaks when the shutter is fired, is fully open, begins to close, and is fully closed. The time elapsed between when it is fully open and begins to close is the shutter speed.
Some shutters, like Copal, produce a fair amount of background noise while the shutter is open, so it doesn't work as well with these, particularly for the higher speeds. But for older shutters like Compound and Ilex, where testing is more of a necessity, it's not a bad method.
Sound method? No it's based on light. Instead of using a mic use any photo transistor or diode from Radio shack, be sure to orient the polarity properly so it'll be sensitive to the light beam. Plug that into the mic jack of your sound card input, run cool edit 2000 to measure the timing. It works great adn is accurate to about 1/1000sec.
If you need some screen shots or help, e-mail me at AUTOMAX1@JUNO.COM