Zeiss Luminars, Olympus bellow head lenses (they were/are 20 mm and 38 mm in focal length), Leitz Photar lenses. I'm sure Nikon and others make the same type 'micro'-lenses as well.
Mind you, they only cover large formats at high(ish) magnifications. But then, that's what they are made for.
Different focal lengths are not chosen to get a different field of view, but are optimized for different magnifications (or rather, ranges of magnifications), so are chosen to match the magnification you're after.
As a rule, the higher the magnification you are after, the shorter the lens that's best suited. (For instance: the 16 mm Zeiss Luminar is best for 10 - 40 x, for a bit less, 6 - 25 x, the 25 mm Luminar would be better.)
Last edited by Q.G.; 01-02-2011 at 07:42 AM. Click to view previous post history.