Repro-Claron f/9 210 mm

[Phil]

Greg,

From the archives - lots of good info. (in German)

http://www.schneiderkreuznach.com/ar...pro_claron.pdf

I've got a 485 - also f/9 - and it's a huge hunk of glass.

Phil

[Greg Lockrey]

Greg,

From the archives - lots of good info. (in German)

http://www.schneiderkreuznach.com/ar...pro_claron.pdf

I've got a 485 - also f/9 - and it's a huge hunk of glass.

Phil

Thanks Phil, I actually got through with some of it with the diagrams.

[Mark Tweed]

Greg, I have this same 210, close to the same year of production as yours - I also have the 420mm version. These are superb lenses. I use them for landscape work and they fantastic for that, sharp like an Artar and incredibly compact for their focal length. I have the Kodak 203mm Ektar and a 270mm RD Artar and these dialyte designs, like the Repro Claron are stellar performers.

I'll sacrifice the slower f stop speed and coverage of these lenses in preference for their smaller size and weight over the traditional f5.6 Plasmat designs, because I backpack often with my large format systems. They're perfect for my field use.

Enjoy your new lens.


Mark

[Pete Watkins]

I have used my one with a front mounted Copal/Polaroid 1 shutter to capture a few portraits on 4x5, and the sharpness of the image is stunning. Sharp as a razor.
Pete

[Mark Sampson]

Somewhere on this site, in another thread about this lens, it was suggested that the Repro-Claron went away after Schneider aquired the rights to the Goerz designs and names. After that Schneider produced the Apo-Artar line, which had the advantage of a more famous nameplate and no thorium glass, until the early 1990's. I can't say if that's true, but it seems plausible.

[walter23]

I don't think you have to worry about the radioactivity unless you grind it up and breath it in, or eat it. I think thorium is an alpha emitter, which means the radiation can barely get more than an inch through the air, and won't even get through your skin.

[Greg Lockrey]

I don't think you have to worry about the radioactivity unless you grind it up and breath it in, or eat it. I think thorium is an alpha emitter, which means the radiation can barely get more than an inch through the air, and won't even get through your skin.

Thanks, it doesn't matter at my age. It would take too long to kill me and I would probably be already dead by then anyway.

There has been some interesting tidbits of information about this class of lenses.

[Arne Croell]

Somewhere on this site, in another thread about this lens, it was suggested that the Repro-Claron went away after Schneider aquired the rights to the Goerz designs and names. After that Schneider produced the Apo-Artar line, which had the advantage of a more famous nameplate and no thorium glass, until the early 1990's. I can't say if that's true, but it seems plausible.

There was some overlap for a few years - Schneider acquired Goerz in 1972 and the Repro-Claron was made until at least 1978/79 (I have a 305mm/12" Repro-Claron with serial no. 13504xxx, that is a production date between 1978 and 1979). That lens, btw, is not radioactive, Schneider changed the design in the mid-seventies, compare this older thread: http://www.largeformatphotography.in...on+radioactive
One question in my mind is - when the Repro-Claron ceased to exist, was the later Schneider Apo-Artar design the same as the previous Apo-Artar or the last version of the Repro-Claron under the better known name? Or another redesign?

[Michael S. Briggs]

I don't think you have to worry about the radioactivity unless you grind it up and breath it in, or eat it. I think thorium is an alpha emitter, which means the radiation can barely get more than an inch through the air, and won't even get through your skin.

It is true that natural thorium, Th-238, is an alpha emitter, but Th-238 decays into a series of radioactive isotopes, which together emit a mixture of radiations, including gamma-rays. The Thallium-208 daughter emits a 2.6 MeV gamma-ray. The gamma-rays are much more penetrating the the alpha particles. One might as well minimize the radiation dose to people by keeping lenses with Thorium glass at a distance when not in use.

[Greg Lockrey]

It is true that natural thorium, Th-238, is an alpha emitter, but Th-238 decays into a series of radioactive isotopes, which together emit a mixture of radiations, including gamma-rays. The Thallium-208 daughter emits a 2.6 MeV gamma-ray. The gamma-rays are much more penetrating the the alpha particles. One might as well minimize the radiation dose to people by keeping lenses with Thorium glass at a distance when not in use.

Just so you know Michael, Water and I are political antagonists.


Just KIDDING, Walter!