Vlad,
Sorry, not ready for the original theory.
The meters were, of course, calibrated at the factory, using some sort of reference light. Determining accuracy and precision (not the same thing, can explain if needed) can be done using special instruments and procedures, and certainly the meters, just like the shutters or lenses, were found of higher and lower performance.
But once again - my main question - if they indeed differentiated between meter grades - why not bring it up in the manual, or passport (where other important parameters, like resolution of the lens, are recorded). What is the point of grading meters if nobody knows about it?
Interestingly, Victor Suglob's book, as comprehensive as it is, does not even mention these letters.
Maybe the serial number engraver was bored and introduced letter A for fun, and then made it "square" A, and was bored still, started adding B, and then retired (or got arrested).
quote:
Originally posted by Vlad
damn! 
. Thanks for doing this work Yury! So what about circling back to precision as to original Anatoly Zilbert's theory? As the GOST specification is from early 60s and these Kievs are from 1950s, it does cast a doubt but I wonder how does the precision gets measured in order to classify the meters?
Vlad
