Made by Tomioka Optical of Tokyo, Japan for Yashica. Yashica “allowed” a few of their Auto Yashinon 55mm, f/ 1.2 lenses to also carry Tomioka’s name. This is a M42 mount lens.
The serial number (lowest found so far) decodes to – No. 5520128 which is ‘552’ is the lens model number (55mm f/ 1.2) and the ‘0128’ is the production sequence number. 128 being the 128th lens made.
These super lenses in excellent condition bring around $800 to $1200 depending on the goodies that might be included (front and rear caps, case) and what not.
Chris
Chasing Classic Cameras with Chris 
I found a tomioka with a aerial number of 1… Could this be a prototype?
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WoW! I’d love to see a few pics of it. While it could be a prototype from what I’ve seen from Yashica is that they would use meaningless serial numbers for pre-production lenses and lenses that are in the wild would be numbered correctly. Cool stuff!
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Hi Chris – I just found this thread while trying to answer a question about Tomioka serial numbers (no luck) but suspect there may be more to those numbers on the 55mm f1.2 as I have two with what would seem to be very high numbers (8 digits), the key one being 55295232 – there’s no way Tomioka Yashica produced over 95,000 of these fast lenses. What am I failing to grasp? More worrying is that although that particular lens is in my inventory, I can’t find it! I’ve dug out 55200927 but the other one has gone walkabout… 😦
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Hi, Graham! I don’t know if Tomioka used a serial number that mere mortals can decode. I know that 55 is the focal length, 2 is for F1.2, and the sequenced production numbers should be the last digits. Could it be the total units produced across all brands? The lens had many different brand names. Would 5,232 be too low if you throw out the 9? Hope you find it soon! Regards, Chris
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