Are you sure Contax's figure? I remember Canon New F1 claim very high
precision, it was only 0.02mm. If my memory serve, some pop photo's
lens reports the field curvature was in the order of 0.1mm. Film plane
to lens mount distance does not provide any information to focusing
accuracy. It only affect the focusing scale on the lens (e.g. infinity
mark accuracy). The focusing accuracy only depends on the mirror
position adjustment.
On the other hand the parallelism of lens mount to film guide is very
important.
C.H.Ling
Chip Stratton wrote:
>
> Except that Gary's measurements are at best only accurate to about 1 part
> in 300, or about .15 millimeter, whereas the close tolerances for the Contax
> are on the order of .005 millimeter. That makes it difficult to say with
> any certainty that Olympus did not adjust the flange to film plane
> distance at some points in the OM line.
>
> To make any real judgement, it seems that what we need to know is what the
> curvature of field of a 'normal' lens is at the film plane: how 'deep' this
> curve is from corner to center at the film plane in millimeters (or microns,
> etc.)
>
> Chip Stratton
> Whose head is reeling from trying to phrase that clearly...
>
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