情事針寸II:
Jos Schneider & Co Kreuznach Doppel Anastigmat Jsconar f:4.5 F - 13.5cm 2 groups 4 elements
情事針寸II:
Disassembly Boyer Paris Saphir <<B>> 50mm F 3.5Lens Structure : 2 Groups 4 Elements, looks like a Double Gauss lens - not certain. Obviously not the same lens structure as Saphir <<B>> 100mm
情事針寸II:
SOM Berthiot Perigraphe 1 : 6.8 F 150 Série VIRight Summicron M 50mm F 2.0 for the comparison