03/27/2020 19:20
Hello Fred!
No, it's not the serial number, you have this additional digits on almost all lenses. It is probably about inspection / quality control.
As of why the serial is missing, we don't know but several lenses without such exist. Maybe it was simply forgotten during production, maybe it was repair...
I do not know enough about FED 50mm f/3.5 to give an estimate on which FED NKVD series this lens should have belonged, can we distinguish 'b' from 'e' leses without serial?
What is the history of this particular lens?
03/28/2020 17:45
I think this lens was made from 2 other lenses.
First of all please note the lens is coated. All lenses for FED NKVD were not coated.
03/29/2020 05:41
That's right, glasses are coated, so it seems to be made with different parts...
Thank you very much!
Fred
