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- What is the shape of the focal plane? 5 answers
The spatial locus on which a lens/camera focuses (and so appears sharpest in the resulting image) is always referred to as the "plane of focus". My question is why does it have to be a plane?
As I understand it, focus is determined by the distance from the subject to the lens and so by this logic the locus of focus should be a sphere (or more precisely a spherical shell) rather than a plane.