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View Full Version : mounting a GG ( come from a sinar) on a technikardan S 4x5



giancatarina
11-Jan-2002, 18:01
i've just bought a ground glass, it cames from a sinar, and i want to mount it o n my technikardan S 4x5 because i need cut angle, and mark for 6x7. the size se ems ok, can i do it ? thanks

Michael Kadillak
12-Jan-2002, 10:00
Two issues. Leaving the issues of the 6x7 aside for a monent, first thing you will need to do is calibrate the new glass to its proper zero focus position. Taking any ground glass and swapping it between camera manufactures is a hit and miss proposition that I would not leave to chance. The proportions of the length and width will be standard, but the thickness of the glass is anything but standard.

Secondly, why not purchase a Linhof ground glass with the 6x7 marks already etched on it. Linhof has many selections for ground glass. In the long run you will be professionally (dead on focus) and financially better off than trying to make the Sinar glass work and find a way to find the 6x7 proportions.Try Robert White for this product in England. Good Luck.

Bob Salomon
12-Jan-2002, 13:13
<Two issues>

No issues here. <first thing you will need to do is calibrate the new glass to its proper zero focus position.>

No you don't. The frosted side is the side facing the lens and it rests on the Linhof focusing shims in the back. As they are in direct contact with the shims the focus plane is the same.

You are confusing the issue with replacing an inside fresnel with an outside mounted fresnel or usin the Bos screen.

In these cases the focus must be adjusted but a TK never was designed for an inside fresnel.

< Taking any ground glass and swapping it between camera manufactures is a hit and miss proposition that I would not leave to chance. The proportions of the length and width will be standard>

Actually they are not.

<but the thickness of the glass is anything but standard. >

But this does not make any difference when the ground side of the screens face the lens and rest on the shims.

So if the Sinar glass is long enough and wide enough it can be used with no focus plane adjustment necessary. Thickness may mean it fits too tightly or too loosely under the holding clips or it may be too long, too short, too wide or too narrow but focus point is the same.

giancatarina
12-Jan-2002, 14:04
thank you Bob, i was thinking exactly things like you describe, now i feel confi dent, i can do it

Michael Kadillak
12-Jan-2002, 19:10
After you get it installed, let us know how it works out.

giancatarina
13-Jan-2002, 10:59
actually, i can't mount it, it's too large 101.5mm. Anyway, i found out that the 6x9 and 6x7 marks where smaller than the real size of my super rollex backs. At the end, i've cut a 6x7 frame in a yellow acetate sheet, so i can clearly see my 6x7 frame, and still can see thinks place outside of the frame ! i've put this thin layer betwen the GG and the fresnel.

Bob Salomon
13-Jan-2002, 11:30
021805 is the Catalog Number for the Linhof 4x5" GG with CM grid and 6x7 markings. It has a list price in the U.S. of $48.00.

001643 is the Linhof GG mask thatis supplied with all Linhof backs. It is an overlay that shows 6x6, 6x7, 6x9 and 6x12 CM Linhof formats. It has a list price in the U.S. of $25.00.

Why not just get these from your closest Linhof dealer? They are not particularly expensive, fit properly, show the proper sizes in the proper place for Linhof and are very easy to install.