I identified it as an FJW Industries 54mm f/1.2. I know of no Kowa connection to that lens. You were asserting you "have seen CRT lenses of similar specification like the one made by Kowa". So I was wondering if you could point me to info on that Kowa CRT lens.
On a related note, I came across some information on the use of the Nikkor-O 55/1.2 and JML ESDS 56/1.2, on a dpreview forum posted by someone under the name mynakedsoda:
The lens is the JML Optical 56mm f/1.2. First some history on this lens. During the 1960's and 70's the US Atomic Energy Commision contracted with EG&G Energy Measurements to build special purpose cameras to record the faint traces on that would appear on CRT screens during atomic tests. The first cameras used Nikkor 50mm 1.4 rangefinder lenses while later cameras used the more application appropriate Nikkor-O 55mm 1.2. The final cameras produced by EG&G used the JML Optical 56mm 1.2. It appears that JML was hired to produce this lens because the Nikkor-O was no longer available. I have personally never seen nor held the Nikkor-O but was informed by the previous owner of this lens that the similiarities between the two (he has owned mulitple copies of both) are striking and it is obvious that JML had the Nikkor in mind when producing this replacement. He even went on to inform me that while he could see little difference in the final sharpness both could achieve, he felt the JML reached peak sharpness sooner (f5.6) than the Nikkor (f8) and ehxibited slightly less CA at wide open to approximately f4. I have no way to confirm this myself but if it is even the equal of the Nikkor then I consider myself most fortunate considering the opinion that experts such as Bjorn Rorslett have of this lens, "The 55 f/1.2 CRT Nikkor is very very sharp at f/1.2 and amazing at f/1.4, at least my sample starts to delcine at f/8 and even more at f/11. It must be one of the all-time best performers ever made by Nikon." High praise indeed from the man that's used literally hundreds of Nikkors if not more!
My guess is that both JML and FJW designed a replacement for the Nikkor-O 55/1.2. The JML version (56/1.2 ESDS 109) appears to be the one actually used, I don't know if the FJW 54/1.2 ESD 109 was. Mine was new old stock, still wrapped in paper, and it doesn't have a serial number, the large box marked S/N is completely blank.
