Technika question

[Noah B]

I recently acquired a nice III and the ground glass was pretty dirty so I took it out and cleaned it. I noticed some small shims in each 4 corners where the GG gets screwed in. They got scattered around the frame when I was putting the GG back in and I was wondering how important those shims are with focus? I don't remember how many shims were on what corner, will this throw my focus off when I go to shoot?

[Bob Salomon]

Critically important. One shim per corner. Call Nippon Photo Clinic in NYC if you need more of them. And, if they are not positioned properly you will not be in sharp focus.

[Noah B]

I have 14 of them, 6 are a thicker than the others. Is there an easy way to go about measuring? Also, is it normal to have that many? I was surprised to find that much for the GG.

[StoneNYC]

I have 14 of them, 6 are a thicker than the others. Is there an easy way to go about measuring? Also, is it normal to have that many? I was surprised to find that much for the GG.

If you have a digital back it would be easy, otherwise you'll go through a lot of film testing...

[Bob Salomon]

If you have a digital back it would be easy, otherwise you'll go through a lot of film testing...

Or send it to the service center. It probably needs a CLA anyway since it is at least 54 years old, if it was the last one made.

[Andrew]

I'm pleading ignorance but 14 shims sounds like too many.... Bob, could a previous owner have done a home fix on the equipment or is that correct?

my guess is that the distance [depth] from the front of frame to the ground glass should be the same as from the face of the film holder to the film and you could measure that with a good depth gauge to within a fraction of a mm and see if it's ok.

I can't quote the number but there will be an acceptable tolerance of some fraction of a mm for the spacing you're looking at but I'd be more worried about generating uneven points of contact and stressing the ground glass when it's clamped down

maybe you should be looking for a technician to help you?

[Noah B]

Thanks for the input gentlemen, I just made a measurement and without the shims, there's about 1/16th of an inch difference between the film holder and the ground glass. Since I have so many shims I think I can put them in place and get it lined up. I just can't believe there were that many in the GG frame, good gracious!

[Andrew]

if I was doing that I'd get a scrap film and measure from the face of the film at multiple points around the holder then repeat the measurements with several holders to get an average to work from

[Bob Salomon]

I'm pleading ignorance but 14 shims sounds like too many.... Bob, could a previous owner have done a home fix on the equipment or is that correct?

my guess is that the distance [depth] from the front of frame to the ground glass should be the same as from the face of the film holder to the film and you could measure that with a good depth gauge to within a fraction of a mm and see if it's ok.

I can't quote the number but there will be an acceptable tolerance of some fraction of a mm for the spacing you're looking at but I'd be more worried about generating uneven points of contact and stressing the ground glass when it's clamped down

maybe you should be looking for a technician to help you?

I have never seen more then one per corner on a modern Technika but I never worked on a III.

[Bob Salomon]

Thanks for the input gentlemen, I just made a measurement and without the shims, there's about 1/16th of an inch difference between the film holder and the ground glass. Since I have so many shims I think I can put them in place and get it lined up. I just can't believe there were that many in the GG frame, good gracious!

"about 1/16th of an inch" will never be precise enough for proper gg placement.

[Noah B]

one can try, EDIT, just went and got a better ruler, looks like there is 1/32nd an inch difference with film in place

managed to get the correct distance, thanks for the input everyone!

[koh303]

Thanks for the input gentlemen, I just made a measurement and without the shims, there's about 1/16th of an inch difference between the film holder and the ground glass. Since I have so many shims I think I can put them in place and get it lined up. I just can't believe there were that many in the GG frame, good gracious!

Most likely this III had a fresnel lens at one point in time and the GG clamps were adjusted to suit. White the SAE system is not nearly as accurate as it could be if you were using a micrometer caliper, nothing on that camera would have been spot on even if you did not mix the shims up. You can adjust fairly simply with a good lens and a good ruler, it would not be the same as it came out of the factory, but would not be far.
Unless you are shooting macro, with wide apertures, you should be just fine. I never expect any folding camera (including my DLC) to have that level of exact film plabe to GG correlation.

[koh303]

one can try, EDIT, just went and got a better ruler, looks like there is 1/32nd an inch difference with film in place

managed to get the correct distance, thanks for the input everyone!

+1 !!! good work.
Now - time to go metric :)