Convertible tessar?

[Dan Fromm]

http://cgi.ebay.com/5x7-Baush-Lomb-Convertible-Zeiss-Tessar-Series-IIb-/270570775857?cmd=ViewItem&pt=Camera_Lenses&hash=item3eff466531 Its a B&L Tessar IIb.

I know that a tessar's rear group will form a crappy image, didn't know that anyone offered tessars as convertibles. Its been a while since I looked at B&L catalogs on cameraeccentric.com, don't recall seeing B&L make the offer. Protars, yes, Tessars, no.

My best guess is that the lens was reshuttered in a Volute engraved for a convertible lens. Any suggestions? Oh, yes, the obvious: I don't know everything. Guilty as charged.

[c.d.ewen]

Any suggestions? Oh, yes, the obvious: I don't know everything. Guilty as charged.


I'd say you know more than the seller.

Here's some of his feedback:

Not As Described Buyer Protection Refunded $330 Received Many Abusive Emails

"barrel...some signs of usage but i see no scratches" =IRIS STUCK tons scratches

and, of course:

L'objectif ne couvre pas le format annoncé par le vendeur en utilisation normal



Charley

[goamules]

Yeah, it was me that asked about IIb's being convertible a while back. I just checked mine again and it's barely an image with just one cell. I don't think they were ever intended as convertibles. This seller is just guessing....

Didn't B&L sometimes sell a shutter with both a wide angle and another set? That would make more sense here. The other aperture range on the plate of this seller's starts at F16.

[Jim Galli]

This is indeed very curious. This is the same guy that was fussing at me about the discussion of the Pinkham Smith Petzval. A bit of a know-it-all.

f6.3 could also be the starting point of a Protar VIIa, but then the second scale beginning at f16 doens't make good sense. It would start at f12.5. Common shutter for two different sets of cells as Garrett suggests seems the only reasonable solution to me. But that doesn't play very well either as in the Bausch Lomb family, you jump from f12.5 for Protar IV to f18 for Protar V, so again, why the f16? Very curious. Buyer beware.

f 16 on that second scale computes to a lens of 152mm.

[BrianShaw]

... but he looks like such a kind and knowledgable gentleman.

[Robbie Bedell]

Dan That lens on the bay is exactly the same as mine, shutter and all, and mine sure isn't a convertible.

[Dan Fromm]

Thanks, Robbie. I had me doubts.