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Steve Hamley
21-Aug-2011, 06:55
Folks,

First, thanks to Dan Fromm and Mark Sampson who commented in my thread on the Carl Meyer Tessar.

It's a rainy Sunday morning here, so let's look at a Tessar that I have never seen another like, or even heard of. I may have commented sometime in the past about this lens, but a quick search did not find it and I'm fairly sure I haven't posted an image.

The lens is an uncoated 32 cm f:5.5 Schneider Xenar, and like the Carl Meyer, I really bought it for the Compound #4 shutter and the adapter, and found it too nice and unusual to cannibalize. I don't think I've seen another f:5.5 Xenar. The serial dates it to about 1939 as best I can tell, and the cool extended adapter was originally mounted on an early Technika board, 6x9 I believe, and I had S.K. Grimes remount it on the pictured Tech IV clone board.

Another unusual thing is - no schneideritis at all, not even a hint! The glass is as clean and clear as the day it was made.

So tessar and old lens people, does anyone know anything about it? Speculation anyone?

Cheers, Steve

Louis Pacilla
21-Aug-2011, 09:15
Hi Steve. Mystery solved.

The Schneider Xenar f5.5 was like the Zeiss Tessar f6.3 IIb . For better corrections & a little larger image circle than the Tessar f4.5. Most manufacturers made the Tessar design in varying maximum f stops. Zeiss Tessar f2.9/f3.5/f4.5/f6.3-----Schneider Xenar f2.9/f3.5/f4.5/f5.5

Maybe Schneider figured out that the corrections at f5.5 are equal to the corrections at f6.3 or so close that the difference is nearly undetectable. Schneider probably thought they would out sell the f6.3 Tessar being about 1/2 to a 1/3 a stop faster at f5.5 and about the same IC and corrections.

Here's the Schneider catalog from 1939. Funny though no 32cm f5.5. They stopped at 30 cm f5.5
http://www.cameraeccentric.com/html/info/schneider_2.html

Steve Hamley
22-Aug-2011, 16:46
Thanks Louis.

Cheers, Steve

Lynn Jones
22-Aug-2011, 16:53
I'm pretty sure Steve, that the f5.5 was because of the maximum shutter opening diameter. Quite a number of lenses around the world has max apertures for the same reason.

Lynn

Steve Hamley
23-Aug-2011, 03:39
Thanks Lynn,

That's likely right; it's a 32cm lens in a Compound #4, and 30cm f:4.5 lenses take a #5.

Cheers, Steve

Paul Ewins
23-Aug-2011, 06:29
I think it may actually be a prototype. The serial number dates it to 27 Nov 1940, but also makes it part of a batch of 300 5cm f2.8 Xenars. I searched through the production records from 1938 to 1946 and couldn't find any 32cm lenses at all, but did find one 36cm/5.5 Xenar produced on 13 July 1939. I have catalogs for 1931, 1935, 1939 and 1950 and none of them mentions a 5.5 Xenar larger than 30cm and that is only in the 1939 catalog. By 1950 the 5.5 Xenar had been dropped altogether.

I do own a 32cm Xenar, but that is a 32cm/3.5 Aero-Xenar from the Gottingen factory which has a completely different serial run. AFAIK that is the only other 32cm lens Schneider made during that period.

Sevo
23-Aug-2011, 07:00
A one-of-a-kind special order item is more likely than a prototype - a narrower version of the mainstream standard lens probably was nothing ever prototyped, but merely mounted ad hoc whenever a customer could not fit the regular f/4.5 one on his camera.

Steve Hamley
25-Aug-2011, 15:04
Just a final note, I compared the difference in bellows draw to a 300mm lens, and it does indeed appear to be 32cm.

Cheers, Steve