juiper glass coatings

[Red Robin]

While searching "da Bay" for RF glass I noted that some lenses had a decidedly blue hue while others displayed a slight red hew. No doubt it was the coatings, but which is better? Does it hint at the time of production? If so when did it change? I've searched around but did't find much. Thanks Red R.

 

[Sonnar Brian]

You can usually determine the date of manufacture of a J-3 by the first two digits in the Serial Number. I find those from the 1950s to be the best. There was a manufacturing cross-over from KMZ to GOMZ in 1956, and a learning curve involved. Some early 1956 GOMZ J-3's were part of that learning curve. Otherwise, all that I have seen are good.