>Typically, designers measure the curvature of field in their most
>popular lenses. They then design the body so that the arc projected by
>those lenses has its midsection corresponding to the film plane. In
>another words, focusing on the center of the image DOESN'T bring the
>center into perfect focus, it brings detail half-way out into perfect
>focus. The corners will be slightly underfocused and the center
slightly
>overfocused - which represents the best compromise possible. They only
>better solution is to electronically couple the lens and body so that
>the lens tells the camera its curvature of field and the camera
>compensates for it. Obviously a solution only for auto-focus cameras
or
>those with moving film planes, like the Contax AX.
>
>Gary Reese
So, are macro lenses "flat field"? I assume this is because the depth
of field under macro conditions is extremely small, and any significant
curvature of the projected image will seriously degrade the resolution?
Are macro lenses typically also "flat field" at infinity focus, or just
at a predetermined reproduction ratio?
Be seeing you.
Dirk Wright
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