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Axon990
20-Dec-2011, 16:53
Hi everybody,

I have a 3x4 Anniversary Speed Graphic. It came with the original Graphic back. I bought a Graflok back from a member of this forum and installed it. There begins my trouble. Although he assured me it would work, it traps the focal plane shutter when screwed down. Okay, whatever. I use slow film and shuttered lenses. I can deal with that. But recently I've noticed focusing errors. On a landscape shoot, it consistently focused in front of the focus point I thought I set. I confirmed this with backyard focus testing today. Clearly I have installed the back incorrectly, or it was never meant to fit on my model of camera.

Can anyone here shed light on my situation?

Bill_1856
20-Dec-2011, 18:47
On my 3x4 Pacemaker Speed Graphic, the Graphic, Graflex, and Grafock backs are truly interchangable, but the infinity stops must be relocated for the Graflex back.

Drew Bedo
20-Dec-2011, 20:23
Bill makes a good point. Are you using the ground glass to focus?

At a workshop in Santa Fe many years ago, the presenter, Steve Simons said. "The Ground Glass is truth."

Jason Greenberg Motamedi
20-Dec-2011, 22:10
The regular 3x4 spring backs which came on those cameras sits a bit closer to the lens than a graflock, so you will probably have to relocate the infinity focus and perhaps also the rangefinder.

Axon990
20-Dec-2011, 22:23
Yeah, I was using the ground glass. What is the procedure for installing a new back? All I did was remove the four screws above and below the glass panel. I found this on APUG: "Yes, the back will simply unscrew. I don't know about the pre-anny models, but on my 1946 Anniversary, I was able to install a 3x4 Graflok with no problem..." What am I doing wrong that prevents the focal plane shutter from functioning?

Since I'm using the glass and not the rangefinder, isn't my problem lack of consistency between the glass plane and the film plane?

Jim Noel
21-Dec-2011, 08:37
Yeah, I was using the ground glass. What is the procedure for installing a new back? All I did was remove the four screws above and below the glass panel. I found this on APUG: "Yes, the back will simply unscrew. I don't know about the pre-anny models, but on my 1946 Anniversary, I was able to install a 3x4 Graflok with no problem..." What am I doing wrong that prevents the focal plane shutter from functioning?

Since I'm using the glass and not the rangefinder, isn't my problem lack of consistency between the glass plane and the film plane?

The simple answer to this question is "Yes". I can't imagine what is causing the problem, or the problem with the curtain hitting part of the back.

Leonard Robertson
21-Dec-2011, 10:34
I looked inside a 4X5 Anni with the back off, and don't see anything obvious that might go wrong in changing the back. I wondered if one of the screws for the back might split the wood body causing a splinter to jamb the curtain. It doesn't seem likely on a 4X5, but maybe the 3X4 curtain rollers run closer to the body. You probably need to take the back off again and look inside. Maybe there is something else inside there causing the shutter to drag.

The focus problem sounds like the ground glass may be installed wrong. Is the shiny side to the rear? If not, that will throw focus off by the thickness of the glass. Some later Graphics used a fresnel lens that may have mounted under the gg. If this is missing, it may throw the gg focus off. I can't quite remember how the fresnel fits a Graflock. Carefully measure from the face of an empty film holder to where the sheet of film goes. Then remove your Graflock focus panel and measure from the face of it to the frosted side of the glass. Should be the same distance.

Len

E. von Hoegh
21-Dec-2011, 10:38
"Should be the same distance" minus the thickness of the film. You'll need a dial indicator and a surface plate, a depth micrometer, or a caliper with a depth measuring block attached to make a meaningfully accurate measurement.

Axon990
21-Dec-2011, 13:45
Thanks for all your help. Unfortunately (fortunately?) the ground glass is facing shiny side out. There is no fresnel on either. Here are some pictures of what's going on.

http://imgur.com/a/V4mwD

In the focus test picture, I mis-labeled one of the papers. The one that says 'Graflex' is actually the Graphic back. Focus was set on the other paper, which says "BIG", "medium", and 'very small'. Each test was ground-glass focused with a homemade loupe.

Leonard Robertson
21-Dec-2011, 16:41
I looked at the Graflok focusing panel on another Anni Speed, and it has a fresnel lens in front of the ground glass. If your Graflok was designed to have a fresnel (and I'm not sure all Grafloks did use a fresnel) and it has been removed, it would cause a focusing error equal to the thickness of the fresnel. My fresnel looks like it is about the thickness of the gg, maybe 1/16" or so.

E. von Hoegh is correct about having film in the holder when measuring the depth. For your purposes, even if you don't have a depth mic or anything fancy, you should be able to compare the two backs and see if there is much of a difference in the film planes. You know the original back focuses well for your film holders. So you need to know if the Graflok film plane location is different. A stack of flat washers or spacer of some sort from the gg glass to the film holder side of the focusing panels should show if there is a difference. The actual measurement in thousands isn't as important as finding if the backs locate the gg differently.

Len

Axon990
22-Dec-2011, 21:09
Hi all,

I asked over at the Graflex.org forum and was able to solve the problem. Thanks for your help.

203Ektar
22-Dec-2011, 23:24
Hi all,

I asked over at the Graflex.org forum and was able to solve the problem. Thanks for your help.

That's great. What did did the problem turn out to be?

Mike

E. von Hoegh
23-Dec-2011, 09:35
I looked at the Graflok focusing panel on another Anni Speed, and it has a fresnel lens in front of the ground glass. If your Graflok was designed to have a fresnel (and I'm not sure all Grafloks did use a fresnel) and it has been removed, it would cause a focusing error equal to the thickness of the fresnel. My fresnel looks like it is about the thickness of the gg, maybe 1/16" or so.

E. von Hoegh is correct about having film in the holder when measuring the depth. For your purposes, even if you don't have a depth mic or anything fancy, you should be able to compare the two backs and see if there is much of a difference in the film planes. You know the original back focuses well for your film holders. So you need to know if the Graflok film plane location is different. A stack of flat washers or spacer of some sort from the gg glass to the film holder side of the focusing panels should show if there is a difference. The actual measurement in thousands isn't as important as finding if the backs locate the gg differently.

Len

Correct, any type of gauge will work to compare the two. If the OP was working with a published measurement (which I can't recall), the measuring tools would have been neccesary.

Leonard Robertson
23-Dec-2011, 09:54
http://graflex.org/helpboard/viewtopic.php?t=6183

It is great 45PSS over on graflex.org was able to answer your questions. Obviously a person who knows Graphics, AND is very good at explaining things.

I still strongly suspect your focusing panel originally had a fresnel under the gg, and for whatever reason it has been removed. If so, your gg sits too far forward, by the amount of the thickness of the fresnel. Interestingly, I seem to have the same problem on a 4X5 Sinar Norma, a recent eBay purchase. One of the first things I noticed when I received the camera is the gg is installed backward - frosted side to the rear. Obviously "wrong", or is it? It seems Normas (at least some) originally came with a fresnel under the gg. The fresnel is missing from my camera. So by reversing the gg, someone has moved the frosted side of the gg back by the thickness of the glass. If the gg is the same thickness as the missing fresnel, it would place the frosted side very near the correct position. I need to dig out a depth mic and straight edge and see how far off it may be.

It is nice to hear of someone with an Anniversary Speed. I have 14 Graphics of various ages and sizes, but the Anniversary is my favorite. I think I have four of them, all 4X5. Oddly I never managed to add a 3X4 to my accumulation. I tend to avoid graflex.org since it always gives me Graphic Fever, and I want to buy even more of them!

Len

Axon990
23-Dec-2011, 10:21
Yeah, the glass was just a tiny bit too forward, and I shimmed it using toothpicks. The only measuring device I have is a ruler in 64ths of an inch, I think using a micrometer would drive me to insanity.

I don't think I'm going to bother with shimming the whole back to free the shutter. 1/400 is good enough for me for anything moving I shoot, and if I come across a really cool barrel lens, I'll just swap out the backs. Easier than meddling with infinity stops by moonlight.

Len, I hear you about Graphic Fever. I have a sign posted above my computer that says "You just bought a camera. Stop looking for more." - but it never seems to work.