Bausch & Lomb Lens Date Code

[brian_downey]

Many of you are aware of the code Kodak used to indicate date of manufacture*. It has been suggested that Bausch & Lomb used a similar code in their serial numbers - but the "key" seems to have been lost. Maybe we can reconstruct it. Here's what I propose:

1. Those of you who have a B&L lens with a coded serial number (2 letters followed by some numbers) send me the _complete_ lens info. For example, I have a lens labeled "Bausch & Lomb Optical Co. - Rochester, N.Y.,U.S.A. - Gold Dot - Magenta Dot - Protar V. - 90mm

E.F. - f/18 - UF3271". The rear element has a matching serial number (only). Please also include any other info that might help us date the lens: if you are the original owner, when you purchased it; if your lens is still in its' original box, any other labeling info on the box; any sequence info such as "must be after x because of ... but can't be after y because of ...", etc., etc. Please also include any pieces of B&L history or "lore" that might shed light on this problem.

 

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2. I will collect all your submissions for a few weeks and then re-post them here and to the rec.photo.equipment.large-format newsgroup (and perhaps also the cryptology newsgroup)

 

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3. Hopefully a pattern will develop that will help us decode at least part of the sequence.

 

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As you'll notice in my example, I included every piece of info on lens

with a "-" between parts of the label. I don't know if there will be any changes in the labeling structure that might help us decode the sequence but, just in case, please send it all.

 

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Also it has been suggested that, if the lens is in a shutter, we might be able to use the shutter info tohelp date it so, if yours is in a shutter please also include; shutter type, size, description, serial number.

 

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If the code is like Kodak's, it's fairly simple - two element, direct

substitution, with the second element 1-9 or 0 and the first element 4-9 (the code isn't reported to have started until after WWII --- anybody know otherwise - or when it stopped?). If we're lucky it might be fairly simple -- like if the serial numbers don't reset to zero each year.

Sound like fun??

Please take a second to help. The larger the "example pool" we have, the better our chances of success.

Thanks

Brian Downey

 

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* The Kodak code is CAMEROSITY where C=1, A=2, etc. (e.g. a lens with a serial number beginning with RA was manufactured in 1952).

[bob_fatone]

Can anyone shed some light onto this particular lens . . mfg. date is not really all that important (i don't think) . . but moreover I am seeking background technicals on maximum iamge size covered . . and maybe optical performance that can be expected,

 

The lens in Question is;

 

305MM F4.5 BAUSCH AND LOMB TESSAR IC, YELLOW AND RED DOT

 

Thank you.

Bob Fatone - Niantic, Connecticut (USA)