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Mitya138 Joined: 03 Feb 2011 Posts: 7 |  Posted: Fri Feb 18, 2011 7:44 am Post subject: Vernier Scales
I've posted this at the APUG site, but I figured this is the best place to find an answer.
A while ago I purchased a Speed Graphic and I've spent a month or more trying to calibrate the top-mounted RF on my 4 x 5 with the images I get on the glass with no success. Then, it occured to me that maybe someone had swapped lenses, but not cams. Sure enough, I pulled the cam and found it stamped for 135mm, whereas my lens is the 127mm Ektar.
So, I figured until I find/make the proper cam, I'd use the vernier scales for hand-held shots. My question is, does anyone know of "to-scale" downloadable vernier images that I could transfer to a plate, or should I just suck it up and get out the tape rule and measure the distances myself?
Or, is the real deal out there to be found, and if so, are they as rare as cams?
Thanks,
Mitya |
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C. Henry Joined: 13 Dec 2005 Posts: 360 |  Posted: Fri Feb 18, 2011 2:37 pm
Mitya;
I hate to rain on your parade but the vernier scales are just as lens specific as the rangefinder cams, so if the previous owner changed the lens without changing the cam he probably did not change the vernier scale either.
Both cams and vernier scales show up from time to time on the popular auction site, but you have to know the actual focal length of your specific lens and the cam/vernier scale being offered which may not be exactly the marked focal length.
C. Henry |
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45PSS Joined: 28 Sep 2001 Posts: 4081 |  Posted: Fri Feb 18, 2011 8:10 pm
http://www.southbristolviews.com/
in the left plane click the graflex manuals link
http://www.southbristolviews.com/pics/Graphic/manual-pdf/Grafcamlst.gif
there are 3 to 4 scales each for 127mm and 135mm lens.
http://www.southbristolviews.com/pics/Graphic/manual-pdf/TRFService.pdf
all you need to know about calibrating the top rf.
Graflex optically measured each lens then cut cams according to the measured focal length. Lens that measured .1mm to .2mm got the nearest cam and scale assigned to them as an inch or two focusing error at 6 feet wide open is not that significant. |
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Mitya138 Joined: 03 Feb 2011 Posts: 7 |  Posted: Tue Feb 22, 2011 12:14 am
Thanks guys. I knew the scales were lens-specific, I was just hoping there was a quick and dirty method of downloading one for my lens. Actually, I've got a fence nearby which is conveniently exactly two meters between each post. I can get a hundred meter measurement quite easily. For shorter distances, a tape measure will suffice.
I still can't calibrate the RF until I get the proper cam though, but the link to the repair manual will be helpful when I do. Thanks again. |
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C. Henry Joined: 13 Dec 2005 Posts: 360 |  Posted: Tue Feb 22, 2011 12:40 am
Mitya;
Remember that the Graflex cameras including the Speed Graphic were made in the United States many years ago so the vernier scale numbers are distances in feet, not meters, even if the lens focal lengths of the lenses were stated in centimeters or millimeters.
C. Henry |
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Mitya138 Joined: 03 Feb 2011 Posts: 7 |  Posted: Tue Feb 22, 2011 4:43 am
Oops! Typo. I meant to say I could easily get a hundred "foot" measurement. (100 feet = 30.5 meters). That's probably a more useful distance for me than 100 meters would be. Thanks anyway.
Mitya |
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