09-21-2010, 02:57 AM
[quote name='wim' timestamp='1285023022' post='3019']
Actually, what you describe is the optical vignetting I was referring to, and I do expect a single filter or the absence of a filter not to have any effect on this either, as a lens normally is designed to take at least 1 filter of a standard size and thickness, without causing mechanical vignetting. You can read a little on optical vignetting here:
[url="http://www.opticallimits.com/lens-terminology"]http://www.photozone...ens-terminology[/url]
Spherical aberration is something completely different; you can read more about it here:
[url="http://toothwalker.org/optics/spherical.html"]http://toothwalker.o.../spherical.html[/url]
Kind regards, Wim
[/quote]
Thanks very much for the interesting links as well as the very instructive discourse. Yes I see that this is still an issue of vignetting. I suppose that the lens would have to be significantly larger (in diameter) to minimize the effect at short focal length and low f number? Yet it is already a behemoth!
All the best.
Actually, what you describe is the optical vignetting I was referring to, and I do expect a single filter or the absence of a filter not to have any effect on this either, as a lens normally is designed to take at least 1 filter of a standard size and thickness, without causing mechanical vignetting. You can read a little on optical vignetting here:
[url="http://www.opticallimits.com/lens-terminology"]http://www.photozone...ens-terminology[/url]
Spherical aberration is something completely different; you can read more about it here:
[url="http://toothwalker.org/optics/spherical.html"]http://toothwalker.o.../spherical.html[/url]
Kind regards, Wim
[/quote]
Thanks very much for the interesting links as well as the very instructive discourse. Yes I see that this is still an issue of vignetting. I suppose that the lens would have to be significantly larger (in diameter) to minimize the effect at short focal length and low f number? Yet it is already a behemoth!
All the best.