Originally posted by normhead Have you actually used an 18-135?
I love being able to shoot at f/4 at 70mm with a standard zoom, and the reviews I read didn't really encourage me to buy an 18-135. So, no, I haven't.
Originally posted by normhead At it's absolute worst setting, the 18-135 still has better center sharpness that a 17-70 according to photozone, and photozone seems to have based their tests on one copy of the lens, and probably a very bad copy.
The 17-70, is better at the wide end for edge sharpness in that it's centre isn't as sharp but it's edges are sharper, at 24mm the 18-135 leaves it in the dust in every category, after that it's a trade-off, the 17-70 has better edge to edge sharpness but not as good center sharpness. At least according to photozone.
Except that the 17-70 was tested on a K10D, and the 18-135 was tested on a K-5. The difference in center sharpness and the performance at 24mm can easily be attributed by the reduced resolution of the K10D. So I don't subscribe to your statement that the 18-135 "leaves it in the dust in every category" at that FL. Quite the opposite: if the 18-135 really is about as good as the 17-70, it should beat it hands down, since it has the advantage of the increased resolution.
Besides, it is my experience that center resolution for such a lens is almost never something to worry about. It is the corner/edge resolution where the differences are most obvious.
Feel free to disagree, but let me speak my mind, ok?
Originally posted by normhead As for actual images... look for yourself and see if there's some weakness in this lens you can't live with.
That's always good advice.
Originally posted by normhead Range, IQ, and WR, I'm not seeing what's not to like.
Well, for me it's the variable aperture for one thing. Even forgetting the fact that it's far slower at 70mm, I like to shoot in M mode, and that's best done with a constant-aperture lens.