Originally Posted by CharlesDAMorgan
So earlier rather than late for J3s - any date onwards to avoid?
Shimming is to get the correct lens register for the L39 right I assume.
Thanks all, very helpful!
The very early J-3s are more for collectors, made in late 1940s early 1950s, expensive to buy now, and some might have Zeiss parts/glass to varying degrees combined with FSU made glass/parts. Lens hacker supreme Brian Sweeney did not think these were the best overall, a mixed bag.
Personally I found the early 1960s (JFK era) ones to be the best and fairly consistent in quality, although early 1970s aluminum finish J-3s are very good too. Avoid the final made early to mid 1980s black finish ones, can't really shim them properly, or to be more accurate.. cannot adjust the back lenses grouping like in the older J-3s, although sellers ask top dollar for them because they are not common and pretty and in good shape.