210mm G-Claron Cells - confused or not... ?

[Dave Tolcher]

I purchased this lens from ebay to take the rear cell and replace my shuttered version which has some residual cleaning marks internally. The rear cells are quite different and all the other 210mm g-clarons I looked up seemed similar to mine and not like this one. Could someone help me out and let me know whether this much larger cell is normal for the 210mm or I have bought a turkey ! This is the item I have purchased:

http://www.ebay.co.uk/itm/191048242854

Thanks

Dave

[Chauncey Walden]

Dave, in the photo the first number after the G-Claron looks like a 3 rather than a 2. Is it?

[Dan Fromm]

Dave, there are two types of G-Clarons. Older (s/n up to around 11,000,000 or 12,000,000, depending on who you ask) dagor types and newer plasmat types. Your new treasure's s/n is 13,... so it is a plasmat type.

I have in hand a 210/9 dagor type G-Claron. Its rear cell is straight, doesn't flare like the one in the eBay listing. The one in the listing matches an illustration in Schneider's brochure for plasmat type G-Clarons. This link http://sdrv.ms/1i4czGa will take you to a list of links that includes links to old Schneider brochures.

Check your old lens' serial number.

[Jim Galli]

Dave, I concur. It looks like perhaps someone has gotten confused and installed a 240 G-Claron or maybe even 270 rear element in that lens. Shcneider's original build sheets used to be in their archive section with measurements.

[Dan Fromm]

Jim, I disagree. If you follow the link I gave in post #3 in this thread, you'll eventually come to a 1998 G-Claron brochure that shows a 210/9 like the one the OP is worried about.

[Jim Galli]

Jim, I disagree. If you follow the link I gave in post #3 in this thread, you'll eventually come to a 1998 G-Claron brochure that shows a 210/9 like the one the OP is worried about.

Fair enough. It's hard to judge from a single image. All of the plasmat ones were the same. That one in the image he provided just looks physically bigger to my eye than the normal 210mm G Claron Plasmat rear group. Gut feeling, that's all.

OK, at Dan's helpful archive link, the measurement D2 for outside diameter of the 210 rear group should be 45mm. So if you have your new one in hand, what does it measure?

[jackpie]

This happened to me too. There seems to be a lot of this cell swapping around on Ebay.

http://www.largeformatphotography.in...=1#post1095938

[Dan Fromm]

This happened to me too. There seems to be a lot of this cell swapping around on Ebay.

http://www.largeformatphotography.in...=1#post1095938

Are you sure? I ask because the 210/9 G-Claron I have has a rear cell with no engraving. Its two cells have the same focal length; G-Clarons are perfectly symmetrical so front and rear cells should have the focal length. My little 210 is as it should be. Same goes for the three 240/9 and one 150/9 G-Clarons I've had and sold.

It seems to me that there's a lot of free-floating paranoia going around.

[Andrew]

FWIW, I have almost the full set of g-clarons... both older dagor and newer plasma types (I'm just missing the original version of 355mm if anyone has one :-)

the pic in the ebay page looks perfectly compatible with my newer version of 210mm. As stated before the rear cap is 45mm. The image in the ebay page may be showing some geometric distortion making it hard to assess.

I'd be interested to know a/ what's the outer diameter of your two rear elements? b/ what's the apparent focal length of the two cells when used alone?

that might help work out what you've got if it isn't 100% kosher

[Dave Tolcher]

FWIW, I have almost the full set of g-clarons... both older dagor and newer plasma types (I'm just missing the original version of 355mm if anyone has one :-)

the pic in the ebay page looks perfectly compatible with my newer version of 210mm. As stated before the rear cap is 45mm. The image in the ebay page may be showing some geometric distortion making it hard to assess.

I'd be interested to know a/ what's the outer diameter of your two rear elements? b/ what's the apparent focal length of the two cells when used alone?

that might help work out what you've got if it isn't 100% kosher

Thank you for all your insightful answers.

Outside diameter of the rear element group is 58mm.

The engraving is definitely 210mm. There are no markings at all on the rear cells at all.

The one I had already that I wanted to replace the rear cell is 45mm and has s/n 13462381 engraved on it (rear cell).

Thanks again

Dave