Looking at the test scores for the various WAs I looked at, not one of them matched the test score of the 15 ltd at 5.6 or F8?
We did a similar comparison of the DA* 60-250 @ 90mm and the Tamron 90. Despite the DA* costing us 2K and the Tamron costing us $250 second hand, and despite the fact that their MTF numbers were very similar, we judged the Tamron images to be better. We found the difference to be noticeable, not minimal. Same with our comparison of the DA*16-50 @16 and 15 Ltd. The control of CA and distortion, I'm guessing have way more affect on IQ than most people give them credit for. The 60250 should have more CA control than the Tamron... it's hard to figure this out in the real world. We know they are testing something. We're just not sure what.
There's no sense in doing well on a test pattern 6 feet away, if CA messes up your images that are taken of subjects that are distant from the camera. The Sigma 8-16 apparently has good CA control, but still lacks the initial sharpness of the 15ltd . So , I'm really interested to find out. Will the 8-16's CA control mean that the MTF number becomes as meaningless as it theoretically should be? It's quite possible it was the lack of control of CA that made zooms less "pop off the page" sharp looking. I don't know. I can't really find anything definitive.
But these two lenses offer an interesting test.
Quote: You buy primes because they're smaller, faster and cheaper for a specific focal length.
You can buy a DA*16-50 for about the same money you can buy an FA 31. You still need the 21 and and a 50 as a bare minimum.
Anyone have an example of a zoom that out performs a prime at a given focal length and F-stop or even somewhere in it's range of F-stops.?