I have a Schneider gold dot 14, for my Korona 7x17, and I like that the best. But it's best in the corners after f/11 or f/16, and I also use the Fujinon 360 f/6.3 which is sharper in corners a couple of stops wider, and bigger moves with maybe 40mm wider circle... But that lens is twice or three times the weight and I hate using it. Would be good for architecture, with big rises, etc. Both Copal 3/