If you want some tables on lens equivalents from 35mm to 4x5 here they are ... the problem is that the aspect ratio of 4x5 is different from 3x2 of 35mm, so there are different ways to determine the focal length multiplier to get the same angle of view.
A popular lens set is a 90/150/210mm because they are relatively inexpensive, and will work within the limits of the bellows on just about any camera. Much wider than 90mm, the bellows may not compress enough, and much longer than 210, the bellow may not expand enough. So what camera you buy will influence what focal lengths you can use. There are always bag bellows and recessed lens boards (for short lenses) or extended bellows and extended or "top hat" lens boards (for longer lenses). But one important specification to pay attention to when buying a camera is what the maximum and minimum bellows draw is. If it's 70-300mm for example, you could get away with a 75mm lens (with very limited movements) out to about a 250mm lens or so.
The length of the bellows needs to be equal to the focal length to focus the lens to infinity. If you want to focus closer, the bellows need to be longer. At 1:1 macro, the bellows needs to be 2x the focal length. So if your bellows stretches from 70-300mm, a 210mm lens would be useable from infinity (bellows at 210mm) to about 1:2 magnification (bellows at 300mm).
Anyway, here are the tables. The "3x" rule from 35mm is actually a little wide, but leaves room on the film to crop the edges and crop off any development marks. So a 50mm is a 150mm on 4x5. A 90/150/210 on 4x5 would be a 30/50/70 on 35mm.
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Originally Posted by John Kasaian
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