Question about 210mm Schneider G-Claron

[binglebugbob]

I'm having a 210mm G Claron mounted in a Copal shutter and an aperture scale made for it The guy doing the work noticed that he has a shim left over and asked if I knew if it is needed when the cells are mounted in a shutter, and if so, whether it should go in front of the shutter or behind it

Can someone with a G Claron let me know where it goes or if it is even needed. Just hoping someone can save me the trouble of making a bunch of test shots....

Best to reply by PM.

 

[chris77]

get a a caliper gauge and measure the overall length.
if its the more recent plasmat design it should be 49mm.
a serial nr higher than 12million indicates a plasmat.

 

[B.S.Kumar]

I'm answering here in the hope that it will be helpful to others as well.
a. Shims are used to ensure that the front and rear groups are as correctly spaced as possible. So technically, it should not matter whether they are placed at the.front or the rear.
b. The Copal 1 shutter has a front thread of M40x0.75 and a rear thread of M36x0.75. The design of the shutter does not allow shims to be easily placed at the rear, and they are usually placed at the front.
c. In any case, the diameter of the shim should give the repairer a clue, and he really shouldn't be asking this question.

Kumar

 

[chris77]

I'm answering here in the hope that it will be helpful to others as well.
a. Shims are used to ensure that the front and rear groups are as correctly spaced as possible. So technically, it should not matter whether they are placed at the.front or the rear.
b. The Copal 1 shutter has a front thread of M40x0.75 and a rear thread of M36x0.75. The design of the shutter does not allow shims to be easily placed at the rear, and they are usually placed at the front.
c. In any case, the diameter of the shim should give the repairer a clue, and he really shouldn't be asking this question.

Kumar

+1

 

[Ian Grant]

The G-Claron's were spaced differently when sold shutter mounted, by Schneider, this helps when used at Infinity/long focus. When used for Repro work up to 1:1 the spacing is increased, this is most noticeable with one of the long FL CZJ repro lenses which has a large spacer (think size of the smallest 35mm extension tube) that needs to be removes from the barrel for distance work.

Try it without the shim first, you can add it if needed.

Ian

 

[binglebugbob]

thanks!