Quote Originally Posted by Keith B


I don't use a filter on my 16-35 II. Are you looking at images shot on you 50D or you 1v?


Every so often I go look at the B+W thin UV filter, but the whole lens cap thing kind of turns me off. The only reason I consider it is because of the shallow hood depth of the 16-35 doesn't offer a lot of protection.
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I'm talking about using the lens on my 1V. On my 50D every lens I have is a winner![]


But anyway, even on film printed to 8x10' or scanned to 4000dpi (that's the only handy way to exam my FF sharpness for me), 16-35/2.8L II's corner is somewhat soft to me even stopped down at 16mm. I'm not sure if that has anything to do with the filter. I heard a theory somewhere saying that, when a filter is added to a wide angle lens, light coming from a very big angle bends when going through the filter glass before entering the lens itself, and this makes the corners not very well in focus when the image centre is in focus. Is this true though? My observation is that the corner softness does not seem to be the result of anything going out of focus, more like the lens is just not razor sharp to resolve the detail.


The 16-35/2.8L II needs the filter to complete weather seal, so I'll need to protect it that way.