Re: Speed Graphic Shutter Checking?
Quote:
Originally Posted by
brucetaylor
I bought a shutter speed tested from eBay for about $100. I have a lot of old shutters, and a lot of them are off by a fair amount. As long as they are off consistently they are usable and accurate (if not they are sent out for service). It takes one more variable out of the equation for me with the old gear I use. Why not get one?
Like I said, I think it was finally that period of time when I had become immersed in Hasselblad service work that made me an absolute perfectionist. And even those weren't capable of absolutes. I'm bound and determined to get this speed graphic within 1/4 stop across the range. Probably not possible. But I discovered that straight from the factory, even Hasselblads could be a mile off in their actual tolerances versus printed tolerances. I'm just now studying Graphic FP shutters, and they can be so far off it's a total disgrace. May as well shoot with a box camera with 1 speed as to put up with that kind of inaccuracy. I'll leave off for a couple days and see what responses pile up. But I am looking for someone to crack me over the head and tell me my logic is faulty. Sometimes it takes that. Regards.
Re: Speed Graphic Shutter Checking?
I posted a similar question last year or so... referring to a 1939 3x4 Speed a friend sold me. I don't recall the various answers I got... there was a certain amount of argument. In the end I decided to try it and see. I have used the camera with b/w film and luckily for me the shutter is reasonably accurate; all of the exposures I've made using the FP shutter have been close enough to use, and the shutter doesn't leak light. Luckily I don't have to use the Graphic professionally...
Given the 19th-century design of these shutters, that's good enough. Expecting any Graflex to have the precision capability of a well-adjusted 'Blad (and I've used both types extensively) will only lead to frustration on the user's part.
Re: Speed Graphic Shutter Checking?
Derived from guillotine shutters, also slit timed, the moving curtain was always proven by empirical testing with film.
As more than a few here have already stated.
Look up the repair expert on Facebook and bring your wallet.
Re: Speed Graphic Shutter Checking?
Almost every 35mm SLR has a focal-plane shutter. Technicians and repairmen check and repair them regularly. I see no reason why the techniques used for testing a smaller focal-plane shutter will not work for a larger one.
@ OP: The optical method you mention (with laser) should work just fine. I imagine any optical method that uses a beam and a sensor will work just fine. Why not contact a camera-repair shop and just ask them?
Best,
Doremus
Re: Speed Graphic Shutter Checking?
i have a calumet shutter speed tester and used it for mine.
and
in the end i put a sheet of film ( or paper ) in it, shot 1/2 with a behind the lens shutter
and 1/2 with the FP shutter and compared the negatives
good luck !
Re: Speed Graphic Shutter Checking?
Quote:
Originally Posted by
HT Finley
I disagree vehemently. Like I said, the shutter does not take 1/1000 to move from top to bottom. It takes far longer than that. 1/1000 is when any point on the film is uncovered then re-covered. The whole frame isn't done at the same time. To try to measure whole-frame would not work. This is not a leaf shutter, where whole frame is done at the same time. No, I'm not getting cranky or condescending. In fact I'm seeking criticism more than anything else. Thank you.
But the digital camera is on B and open during the entire time the slit is travelling, so you will see the entire focal plane, each point exposed for 1/1000s if the speed is accurate.
Re: Speed Graphic Shutter Checking?
Leitz devised a simple shutter speed checker for focal plane shutters. http://www.skgrimes.com/library/old-...shutter-tester
Re: Speed Graphic Shutter Checking?
If you read the instructions and follow them, you can use a Calumet shutter speed tester to measure a Speed Graphics' and Graflexes' shutter speeds. I have one now, have used it with my RB Ser. B and with my Pacemaker Speed. I didn't have it when I got my Speed, so used the test strip procedure described above.
Finley, stop objecting to what is known to work well and start doing.
Re: Speed Graphic Shutter Checking?
Quote:
Originally Posted by
Andy Eads
The Leitz system is more precise and elegant, but essentially what we did long ago by looking through the shutter at an analog television as in post #2. Ultimately the best shutter tester is an oscilloscope and a quite small high speed light sensor. This can also be made to work for measuring shutter delay and flash delay. For non-focal plane shutters a large high speed light sensor works. In years of electronics repair I found an oscilloscope to be the most valuable single piece of electronics test equipment, even more useful than a multimeter.
Re: Speed Graphic Shutter Checking?
Jim, I used scopes at work, but no more work, so I have been looking at the new cheap ones.
And of course a link to the retail devil. The best thing about Amazon is the reviewers. Many are very good at guiding a buyer. If you read a few dozen good and bad reviews.
https://www.amazon.com/gp/product/B0...rd_i=393269011