Originally Posted by Rick Olson
The same challenges exist with lenses by other manufactuerers when the issue is ULF. Virtually all lens manufacturers give coverage at f22 for projection type printing where several magnifications are involved. For ULF works, where we normally would never enlarge more than about 2X, one can generally use all of the circle of illumination (if you stop down enough), which is usually way more than stated coverage.
Another thing you have to take into consideration is that while the lens itself may provide X amount of coverage shutter mounting may reduce this coverage. In theory a 14ĘDagor should cover 12X20 with an inch or two of movements, but in practice many don┤t. In fact, I have even seen a 16.5ĘDagor that would not cover 12X20.
Last edited by sanking; 01-17-2007 at 02:02 PM. Click to view previous post history.