09-20-2010, 10:12 PM
[quote name='wim' timestamp='1284987277' post='2977']
Another question if you don't mind:
What do you mean with little or none with either one <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />? Is it the same fairly sharply delimited mechanical vignetting or just a slight, gradual darkening of the corners, i.e., optical vignetting (which will be worse close to infinity than close to MFD, where it likely will be invisible)?
If it is the latter, you can switch on ALO (Auto Lighting Optimizer; Custom Functions) which will get rid of vignetting in your jpegs if you shoot those or process your images in DPP.
BTW, I did test one or two 17-55s a couple of years ago, and I found it had some vignetting at 17 mm mostly, which disappeared relatively quickly for the largest part when zooming in, or when stopping down a bit.
Kind regards, Wim
[/quote]
I mean that there is still some gradual fall of in image intensity at the corners when the lens is at 17mm and the aperture is wide open. Perhaps this should not be called vignetting, but rather spherical aberation due to using a larger extent of the lens. As you suggest, the effect is minimized as I zoom in a bit or if the aperture is stopped down a bit. I am not 100% convinced that one filter and no filter are any different. Probably the best way to determine that would be to shoot a wall of uniform color and illumination with and without a filter. At any rate, the sharp mechanical vignetting is no longer present, and I am very glad for that!
All the best.
Another question if you don't mind:
What do you mean with little or none with either one <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />? Is it the same fairly sharply delimited mechanical vignetting or just a slight, gradual darkening of the corners, i.e., optical vignetting (which will be worse close to infinity than close to MFD, where it likely will be invisible)?If it is the latter, you can switch on ALO (Auto Lighting Optimizer; Custom Functions) which will get rid of vignetting in your jpegs if you shoot those or process your images in DPP.
BTW, I did test one or two 17-55s a couple of years ago, and I found it had some vignetting at 17 mm mostly, which disappeared relatively quickly for the largest part when zooming in, or when stopping down a bit.
Kind regards, Wim
[/quote]
I mean that there is still some gradual fall of in image intensity at the corners when the lens is at 17mm and the aperture is wide open. Perhaps this should not be called vignetting, but rather spherical aberation due to using a larger extent of the lens. As you suggest, the effect is minimized as I zoom in a bit or if the aperture is stopped down a bit. I am not 100% convinced that one filter and no filter are any different. Probably the best way to determine that would be to shoot a wall of uniform color and illumination with and without a filter. At any rate, the sharp mechanical vignetting is no longer present, and I am very glad for that!
All the best.