One thing to consider is the size of filters. According to a 1996 catalog I have, the Distagon CF 4/40 takes 93mm filters while the CF50 and CF60 take the 60mm filters as would the 80 and other lenses until you get up to the 350 and 500. I have a 50 that I am very pleased with but if you are looking for light weight it is 1lb 12oz and the 60 is only 4oz less. A wide strap is helpful.

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