OK, I see process lenses all the time with this scale/pointer on them, but I can't figure out what it would be used for. The outer ring is clearly the aperture of the lens, but what do the numbers on the inner rings represent?
I've searched archives here, and Google for the last hour, but haven't found anything (probably because I don't know what terms to use, as I was always in editorial, not in the press room, when I worked for a newspaper).
This is purely for my own curiosity, I'm not planning to make offset printing plates anytime soon! Clearly, you wouldn't use the guide for regular large format photos with a process lens.
Bookmarks