In article <4q0b7u$i70@mars.hyperk.com>, glh@srv.net says...
[most deleted...]
>Note that the image circle of a lens does usually increase as the lens
>is focused closer (at least if this is done by moving the lens farther
>from the film), and it also increases for many lens designs as the lens
>is stopped down. This might mean that some 35mm lenses could be used
>for extreme closeup work, at very small apertures, with larger formats.
>I don't know how far you can carry this idea, or what the relative image
>quality would be; maybe someone has tried this?

It works, though the "awkwardness" factor is extremely high (like using
16mm movie camera lenses on 35mm for extreme magnifications), and there
is no shutter. Many 35mm lenses, if reversed, can produce a decent image
on 4x5 film if used for extreme close-ups, but the hair torn out due
to the frustration level involved makes a real mess.....;-)
Hope This Helps