Re:Dirty lens article
by dperfect on Saturday January 31, 2015 @05:51PM
(#8978393)
Adding to what's been said, I believe the worst situation (in terms of seeing dust on a lens) would be:
1) wide aperture
2) depth of field that (even partially) includes objects on the lens itself
In normal situations, these two conditions are somewhat mutually exclusive. That is, a wide aperture decreases depth of field, making it less likely for anything as close as the lens to be in (partial) focus.
The reason you may see the effects of a dirty lens more with fisheye or wide-angle lenses is that they often have a very short hyperfocal distance (bringing most everything into focus), so it's much more likely that condition #1 won't negate the effects of #2. These conditions would also be likely to occur in low-light macro photography.
1) wide aperture
2) depth of field that (even partially) includes objects on the lens itself
In normal situations, these two conditions are somewhat mutually exclusive. That is, a wide aperture decreases depth of field, making it less likely for anything as close as the lens to be in (partial) focus.
The reason you may see the effects of a dirty lens more with fisheye or wide-angle lenses is that they often have a very short hyperfocal distance (bringing most everything into focus), so it's much more likely that condition #1 won't negate the effects of #2. These conditions would also be likely to occur in low-light macro photography.