Originally Posted by coriana6jp
At one time I had 210mm, 240mm, 270mm and 305mm Kowa Computars. I sold the 210mm some time ago and am planning to sell the 240mm and 270mm because the only ULF camera I have now is a 20X24 with a 12X20 reducing back.
Briefly, the 210mm Computar covers 11X14 or 7X17, but just barely. The 240mm Computar covers 7X17 nicely and just covers 8X20. The 270mm Computar covers 8X20 nicely and just covers 12X20. The 305mm Computar covers 12X20 with two or three inches of movement.
The computars are great lenses for the formats they cover because of their wide coverage for the size. They basically have about the same amount of useful coverage as Protar V but have wider aperture and generally cost less. But they cost less mainly because not many people are aware of their great covering power.