12-01-2010, 06:26 PM
[quote name='Lomskij' timestamp='1291210018' post='4650']
... does the image circle projected by the lens expand due to diffraction?
[/quote]
No. What happens is, that the amount of vignetting usually decreases when stopping down,
so the brightness is more evenly distributed over the image circle ... and by stopping
down, the usable imagecricle might quite well expand a little ... but this is not a cause of
diffraction.
... does the image circle projected by the lens expand due to diffraction?
[/quote]
No. What happens is, that the amount of vignetting usually decreases when stopping down,
so the brightness is more evenly distributed over the image circle ... and by stopping
down, the usable imagecricle might quite well expand a little ... but this is not a cause of
diffraction.