# Thread: Speed Graphic Shutter Checking?

1. ## Speed Graphic Shutter Checking?

I couldn't decide whether to post this is DIY or here. There seems to be some overlap. Anyway, after scouring the internet, I haven't found any reliable information on how to check (test) the focal plane shutter on a Pacemaker Speed, or even where to have it done for that matter. I have found some DIY service info, but nothing that looks like a reliable way to find out what my shutter speeds really are. Thank you.

2. ## Re: Speed Graphic Shutter Checking?

We used to check them by looking at an old analog TV screen through the shutter. At 1/60 or 1/30 second, you should get a complete picture with no overlap. At lower speeds there is overlap, but sometimes one could figure out how much and calculate the shutter speed. At higher speeds, you get only part of the picture: 1/2 at 1/125 second, 1/4 at 1/250 second, 1/8 at 1/500 second, and 1/16 at 1/1000 second. These speeds should be checked at top, middle, and bottom of the film gate to check for even exposure. I'm relying on distant memory for the above data, and could be wrong.

3. ## Re: Speed Graphic Shutter Checking?

I tested mine mine by shooting some film and reading the neg. I used a roll film back (square format) so I had 12 test exposures. That gave me ballpark answers that were good enuf.

4. ## Re: Speed Graphic Shutter Checking?

Originally Posted by Jim Jones
We used to check them by looking at an old analog TV screen through the shutter. At 1/60 or 1/30 second, you should get a complete picture with no overlap. At lower speeds there is overlap, but sometimes one could figure out how much and calculate the shutter speed. At higher speeds, you get only part of the picture: 1/2 at 1/125 second, 1/4 at 1/250 second, 1/8 at 1/500 second, and 1/16 at 1/1000 second. These speeds should be checked at top, middle, and bottom of the film gate to check for even exposure. I'm relying on distant memory for the above data, and could be wrong.
I have thought about using CRT sweeps and phonograph records, and all that. Then I remembered we're dealing with a FP shutter here. Matching and mismatching direction of travel of the moving target with the direction of travel of the shutter will yield varying results. Certainly somebody in the 90 years of the manufacture of these cameras has come up with a high quality method of checking the shutter. Shooting film as Brian suggested would be good, but introduces another variable being film processing, unless I were to have an ample supply of color reversal film with its narrow latitude. I originally thought to post this in the DIY subheading, but I haven't even come across a place to send the camera for a high-quality testing job. As an aside, I've spent enough time on these photographic forums to possibly be known as a picky, exacting person. I think it was all that Hasselblad work I did that ramped up my exactitude.

5. ## Re: Speed Graphic Shutter Checking?

Originally Posted by BrianShaw
I tested mine mine by shooting some film and reading the neg. I used a roll film back (square format) so I had 12 test exposures. That gave me ballpark answers that were good enuf.
Test strips -- four shots on the same frame 1/4, 1/2, 3/4 and 4/4 uncovered will economize on film.

6. ## Re: Speed Graphic Shutter Checking?

I bought an optical shutter speed tester off ebay (plugs into my iphone jack) and the associated app. Total cost was around \$30 and it seems to work okay - pretty close when checked against lens/shutters I know are okay. The app outputs a graph showing open/close and measures shutter speed. The seller (photoplug) doesn't seem to be around anymore but it looks like there are similar products. It's no test bench but simple to use and works well enough for me as a first pass. As others have said, the negative will tell the story.

Regards
Dave

7. ## Re: Speed Graphic Shutter Checking?

Here's where I would appreciate somebody poking holes in my logic. Let's take the 1/1000 speed. I believe we can all agree that even perfectly timed, it takes a lot longer for the slit to go from the top of the frame opening to the bottom. That particular travel time is not where the 1/1000 gets it's name. It may well take 1/10 or 1/50th or whatever to actually make the traverse down the fram opening. The 1/1000 designates any point on the film when the top edge of the bottom curtain opening passes and the bottom edge of the top curtain passes over that same point. So, a laser pointer pointed at a receiving sensor arrangement [I]should[I] work.

8. ## Re: Speed Graphic Shutter Checking?

I have done some crude checking of leaf shutters by putting a lit ipad near the focal plane, and shooting a digital camera through the lens towards the pad, then comparing brightness of the digital image timed with the digital camera vs. the analog camera's lens with the digital on B. Should work for a focal plane if you can image the entire focal plane.

9. ## Re: Speed Graphic Shutter Checking?

Originally Posted by hsandler
I have done some crude checking of leaf shutters by putting a lit ipad near the focal plane, and shooting a digital camera through the lens towards the pad, then comparing brightness of the digital image timed with the digital camera vs. the analog camera's lens with the digital on B. Should work for a focal plane if you can image the entire focal plane.
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.

10. ## Re: Speed Graphic Shutter Checking?

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?

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•