Who can tell me about his Bausch & Lomb lens? The main barrel is about 4 7/8 inches long. It is chrome plated. The main barrel fits inside a slightly larger black barrel and the main barrel moves moves back and forth by a geared mechanism. The main barrel is about 2 5/8 inches in diameter. Stamped in white on the main barrel is: BAUSCH & LOMB OPTICAL CO. Rochester N.Y. U.S.A. 3208053. The front element has a black screw off ring which has 15 In. E.F. stamped on it.
David Michael Bigeleisen
I have that lens mounted on my 8x10 right now. It's a projection lens ... a Triplet (not a Petzval) ... no iris. Mine is very sharp and easily covers 8x10 ... I don't know about larger formats.
Physical description and measurements you list are identical to mine ... but mine has no serial number.
Last edited by Jim Graves; 5-Jun-2010 at 18:36.
And ... here's the picture:
These triplets are pretty nice if you're willing to work with their shortcomings, i.e. no iris. They are pretty sharp in the original configuration. If you're into soft focus/ distortions and are willing to spend some time mixing the elements up a wonderful glow is achieved.
All images shot with 15 B&L Triplet with new cell arrangement.
Brian ... can you be more specific about mixing and matching the elements??
Hi Jim, my lens arrived with quite a bit of internal dust so I removed the inner brass tube holding the elements and drew a diagram of the lens arrangement so I could put it back together correctly. After everything was cleaned I had some time to kill so I just started experimenting. Between the elements are brass shims of varying sizes so spacing is made easy by putting the glass and the shims wherever you want. I think I spent 45mins taking apart the lens, changing the elements, back together, looking at the ground glass. Over and over again, always marking the arrangement on a piece of paper so I wouldn't do the same configuration twice. This, to me, was the best out of the bunch. Of course I lost the paper with the proper arrangement and all the notes about the other mixes.
Brian ... thanks ... now I have to try it out. Your shots turned out great.
By the way ... my lens has the following typed sticker on the brass inner barrel:
"When removing lens to clean be sure and replace correctly. The side of the back lens with the stronger curve should be towards the rear. Center lens can be put in either way. Front lens should be put in with the strong side towards the front. The shorter spacer should be between the back lens and the center lens."
I believe this is the arrangement of the classic Cooke Triplet and is very common in "newer" projection lenses ... the thumbnail is an illustration ... the actual B&L projection lens has unequal spacing ... with the front element farther from the middle element than is the rear element from the middle element:
Last edited by Jim Graves; 6-Jun-2010 at 12:17.
WHAT its focal length?Originally Posted by Jim Graves
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