Luminous Landscape Forum
Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: Mark F on May 08, 2009, 05:31:05 pm
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I'm testing the Canon 16-35 2.8L II that I just bought and have concluded that f8 and f11 are sharp, and f5.6 is still usable. But f2.8, 4, 16 and 22 really are not sharp at all. For those of you who own this lens, is this your result too or do I have a bad copy that should be returned? I did my tests at both 16mm and at 35mm with similar results.
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Sharp where? Center? Corners?
My 16-35 II is very sharp in the center wide open, less so through 5.6, then sharpens again at f/8 and f/11. It's very soft to soft in the corners all the way through. Though for some reason I think it's flattest wide open, go figure.
But I mostly use it wide open anyway. If I can slow down and use a tripod, my Sigma 12-24 is much better in all aspects of image quality, and my 24-70 as well.
Edit: I like the reviews here: http://www.slrgear.com/reviews/showproduct...uct/1082/cat/11 (http://www.slrgear.com/reviews/showproduct.php/product/1082/cat/11)
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Hi,
Without samples this is hard to judge. I'd recommend that you take pictures of a brick wall and compare corners. If the corners are different that would indicate a serious decentering issue and in that case you should have another copy.
I do not own the 16-35/2.8L or any other Canon lens, but it's widely acknowledged that lens is not very sharp in the corners. All lenses tend to be diffraction limited about f/11 so loosing sharpness at f/16 is normal (essentially laws of physics).
Best regards
Erik
I'm testing the Canon 16-35 2.8L II that I just bought and have concluded that f8 and f11 are sharp, and f5.6 is still usable. But f2.8, 4, 16 and 22 really are not sharp at all. For those of you who own this lens, is this your result too or do I have a bad copy that should be returned? I did my tests at both 16mm and at 35mm with similar results.
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I use this lens on the 1DS MrkIII and at 16mm it suffers from astigmatism even when stopped down to f8. At f8 it is sharper top right and soft top left and left of centre when I focus towards infinite. If I focus say towards centre forground at f8 both bottom corners are sharp. It suffers from field curvature also which is common among wide angles especially wide open.
I must say centre frame it is very sharp f5.6 - f8.
Lloyd Chalmers seems to have a similar opinion testing this lens in terms of astigmatism.
I use this lens from 16mm - 24mm. At 35mm it is not a great choice for high res prints.
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I tested the lens by shooting a stucco wall from about 20'. I manually focused on a specific point and confirmed with the 1Ds3's AF. I then looked at the images on my 24" monitor at 2:1, homing in on areas that are about 1/3 from the bottom and about 1/6 from the left and right edges.
I know that a stucco wall is not perfectly smooth, but at 20' there should be adequate DOF, especially when I stop down to f16 or f22. Also, f8 and f11 give good results.
Based on the comments posted above it seems that other copies are not especially sharp at f stops other than f8 or f11 either. Is the Sigma 12-24mm for full frame cameras?
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Is the Sigma 12-24mm for full frame cameras?
Yes. Note that it is a slow lens -- both max aperture and AF performance. I only use mine when doing architectural work, on a tripod. But my copy is quite good in terms of distortion, sharpness, and color fringing, even on a full-frame body.
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Thanks to everyone for replying. I've now got to think through whether I can live with only using f8 and f11. I'm leaning to "yes" since I will use the lens for tripod landscape work and speed shouldn't be an issue.
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I owned the original 17-35 and then the original 16-35. I shot lots of images with both with excellent results. About a month ago I traded my 16-35 in for the MkII version. All I can say is WOW!!!
The MkII is definitely sharper across the image. It's better than the original in every respect except for the fact that I had to buy a larger polarizing and UV filters ($300 ouch!). Most of my images are shot in the f8 to f11 range and they are much sharper with better contrast than the original version.
Cheers.
Bud James
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Today I shot across a pond to the far shore, auto-focusing at infinity. Then, I thought I would try live view at 10X and discovered that there is a noticeable difference between what looks sharp in the viewfinder using auto-focus and what looks sharp with live view. Maybe the lens needs a micro focus adjustment?
I never had these problems with my old Mamiyaflex