Auteur: Dan Fromm
Date: 01-01-2005 17:20
Christian, early G-Clarons have 6 elements in 2 groups, a design very similar to the Goerz Dagor. Later ones have 6 elements in 4 groups, plasmat type. The Schneider archive gives more details, shows cross-sections, ...
The two types are functionally equivalent, but I understand that the modern plasmat type has marginally better -- no pun intended -- image quality at the edges. Schneider claims the same coverage for both. See their site. Some users -- look for posts by Jim Galli on http://www.largeformatphotography.info/lfforum/ -- say images made with the Dagor type are somehow more pleasing.
Repro Clarons have 4 elements in 4 groups, are dialyt designs like Apo Ronars, some (not all) Apo Nikkors, ...
Covering 12" x 20" with no movements requires a 600 mm circle. According to Schneider, at 1:1 the 355 G-Claron covers about 800 mm at f/22, therefore about 400 mm at infinity.
I can't speak for my compatriots who report that a 355 G-Claron will cover 12x20. Perhaps they expect less image quality in the corners than Schneider does. Perhaps they're trying too hard to sell lenses. Perhaps they can't read.
Regards,
Dan
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