Originally posted by Des And, as you have said many times Norm, sometimes you need the prime for f2.8. Horses for courses.
Roger Cicala's point would be that the DA*60-250 is likely to have more variation between different copies and at different focal lengths. Photozone could test a different copy and get quite different numbers. (I won't mention the infamous 18-135 review.) But despite his generalizations about zooms v primes, he emphasizes that for practical purposes, the differences won't matter very much, if at all, most of the time: "
Don’t get me wrong. Zooms don’t suck. They’re excellent and very practical lenses. If you knew all the compromises that go into making one, you’d be as amazed as I am that they can make them that good for those prices. Let me add that if forum warriors posted 800 or 1200 pixel-wide images online, you’d probably barely be able to tell the difference between the primes and zooms, much less the differences between the zooms."
In the comments below the article there is a link to this piece by Michael Reichmann from 2009, which is also worth reading:
Sharp - Luminous Landscape
Reichmann emphasises that differences between lenses matters far less than the difference in skills and technique.
But regardless of Roger's point, we do know that with one copy of the DA* 60-250 and one copy of the DA* 200 the 60-250 was sharper. What the results would be if they tested 5 copies of each is another question, but we know at least one the DA* 60-250 came out on top. SO the DA* could win the shootout 4 to1, but the DA* 60-250 has the chance to win 5-0.
My problem with the 18-135 review was his analysis not his numbers. He took some kind of average and declared it to be a really bad lens. 1.5 stars out of 5. The Sigma 18-250 which I owned got 2.5 stars. We have not one Sigma 18-250 image that comes anywhere close to matching the 18-135 images in it's range. HIs analysis was complete nonsense. The higher rating should go to the camera capable of the best images, not some nonsense average edge to edge. IN many images edge sharpness is not important. Meanwhile the the 18-135 had excellent scores in more categories than the 16-50, any 18 to 200-300 type lens, and all of the older Pentax primes, all of which were rated higher, because he averaged in the borders at the long end, and selected lenses that couldn't match the 18-135 to rate higher. The centre wasn't as sharp, usually much lower, they were just plain average everywhere. Who wants that? So it was Klaus' total lack of understanding of what you needed in a lens to take a great image that was the issue. He looked at the numbers and said "lousy lens." I looked at the same numbers and said "great lens, I can use this". Klaus was one of the gatekeepers of the "edge to edge sharpness is the most important thing" club, and the philosophy that said shooting a brick wall was better than a lens that could show depth and have a 3d look. He's not alone in that. It seem to be the current thing. Well if you really want that, you can do a great job with a cell phone.
TO me, a lens that has Centre Sharpness at 135mm is all I need for more than half my images.
If the Klaus's view of the world is right, why do so many of us still love the rendering of the 77 ltd. and 31 ltd, and the DA18-135 shot at 24mm-28mm?