Quote:
Originally Posted by daft_biker
There is no arc - the plane of focus is flat and parallel to the film plane unless you use a tilt and shift lens. And even when you use a tilt and shift lens (or a camera with movements) the plane of focus is still flat, just you can place it at an angle to the film plane.
I agree with your previous point about focus and recpompose being fine where there's enough DoF to cover focus errors.....I do it regularly on my compact. I did say it had it's uses  |
While that's strictly true (and, in several ways, also not true*), as said in the other thread, it's only relevant for extremely narrow depths of field. It's becoming one of those questions where while what you are saying is mostly accurate, it's misleading for the purposes of answering the question. (And I think you could probably make the argument that my clarifications may be muddling the situation more!) I actually found a website explaining it the way you phrased it that's completely logically incorrect, mostly because he's drawing the wrong triangles.
Basically, what I'm saying is while the kind of composition clashing with depth of field is achievable, I would tend toward saying the first question you should be asking yourself in that situation isn't, "Should I recompose", it's "Do I really need this depth of field to be so narrow".
*The fact it's treated as flat while it isn't always is why you have sharpness fall off at corners.