Upload & Sell: Off
surf monkey wrote:
So by that reasoning a lens that appears sharp on a 1MP camera would be just as good on a Nikon D800?
Offering an absurdity as a response doesn't really get at the actual issue, does it?
Since the 17-40 (to use an example) can do a fine job of producing fine art prints at 20" x 30" (and some might argue for even a bit larger), eschewing this lens for reasons of "sharpness" on the 5D3 and not on the 5D is a debatable notion, to say the least - even more so in that the lens has been used with great success by quite a few folks shooting the 5D2.
As I mentioned earlier - and perhaps more than once - you cannot generalize about the sharpness of the 16-35 and the 17-40 without getting a bit more specific about where each lens has its strengths. The virtues of the 16-35 are that it has f/2.8, and that it is "better" in the corners than the 17-40 at the largest apertures, making it a fine lens for those whose primary need is to shoot low light, hand-held, ultra-wide photography.
While getting it if that sort of shooting is what you do makes a lot of sense, getting it to do, say, landscape photography makes little or no sense at all - at least if your approach to landscape is to use the tremendous DOF on the ultra wide, shooting it from the tripod, and typically stopping the lens down. Stopped down, the 17-40 produces excellent image quality across the frame, is more resistant to flare than the 16-35, and uses the more standard 77mm filter thread diameter rather than the larger and slightly unusual 82mm filters. In some tests it appears to produce slightly (but perhaps insignificantly) better center resolution in some situations. It is also a bit smaller and lighter and it costs less.
Both are excellent lenses, and both can produce fine image quality. However, each has its pluses and minuses - so rather than pronouncing one better than the other, it makes a lot more sense to compare both of these fine lenses objectively against your own shooting style and needs. (And if you shoot a cropped sensor body, don't rush out and get either of these just because they have red rings and the sacred letter "L." Looked at objectively, the EFS 17-55mm f/2.8 IS is an all-around better choice among such lenses for most folks looking for a high quality lens for a cropped sensor body with this range of features.)
And no need to start our own "shoot out" of dubious reliability here. There are plenty of test reports and reviews available that we can look to.