Quote Originally Posted by Dan Fromm View Post
I ask because it isn't clear and because, idiot that I am, I have trouble understanding why much the same design should lose coverage over the years. I can understand that ancient lenses shot on ancient emulsions might seem softer than the same lenses shot on modern emulsions and can see how that would lead to the conclusion that way back when they covered more. Otherwise I'm stumped.

Dan
I believe that in later lenses most of the Dagors were mechanically vignetted in order to reduce flare, so even though the design may be the same metal from the shutter or barrel gets in the way.

To note the extremes in coverage I have seen, I once had a 12" Dagor from the 1920s that covered 12X20, and a 16 1/2 Dagor from the 1940s that would not cover 12X20. Of several 14" Dagors I have owned, only one, and the oldest one, woud cover 12X20.

Sandy King