[LargeFormat] C-Claron 190mm f4.5 - Paperweight?

[Michael Briggs]

On 12-Apr-2004 Clive Warren wrote:
> I have just cleaned out the corner of the darkroom and found a C-Claron 
> 190mm f4.5 lens.  This is a bit of a monster and is rather strange in that 
> it has no mounting flange or iris.  The from the curvature of the elements 
> it seems as though it could cover 8x10 and a quick test pointed towards a 
> window seems to confirm that.

> Right, so no iris, no mounting flange, barrel measures about 3 1/4" 
> diameter and is about 3" long, beautiful coated glass and a lot of 
> potential - or is it a paperweight?  Did I mention it is heavy :-) 
> Suggestions please.

The German website of Schneider has an archive of old brochures:
http://www.schneiderkreuznach.com/archiv/archiv.htm.

Two cover the C-Clarons.  "C" is for Copy.  They were for copying machines:
"Kopier-Objektive für Verfielfältigungen": Copier lenses for duplication.

c_claron.pdf has some German text.   There is a diagram of the use in a copying
machine, with a mirror (Spiegel) behind the lens.   Does this mean that the
light rays are supposed to go through the lens twice?

A few interesting sentences with pseudo-translations (no guarantees for
accuracy!):

"Die COPY-CLARONE liegen in glatten Zylinderfassungen ohne Irisblende vor."
--> 
The COPY-CLARONE are provided in smooth cylinder without aperture iris.

"Die angeführten optischen Systeme können natürlich auch in benachbarten 
Bereichen 1:1 Abbildung eingesetzt werden."
-->
The cited optical systems can be used naturally also be used for reproduction
ratios near 1:1.  

ccn.pdf looks to be newer and has the specs for your lens: the picture diagonal
is 364 mm at 1:1 and it has 6 elements in 4 groups.
This document has its right and left portions converted to top and bottom pages
in the pdf file.

--Michael