I recently purchased a K-3 and DA 18-135 WR kit. Wow, this is a magnificent camera and a quantum leap from the K10D I have been using for the last 7 years. I am very impressed with the K-3.
Not long back I purchased a Sigma 17-70 DC HSM Contemporary to satisfy my LBA. It helped make my K10D a better camera.
Yesterday I went to a local marina to test out the K-3. I took two shots of a police boat moored there. The first shot was with the 18-135 and the second with the 17-70. Both were taken at 48mm from almost the same spot.
I have compared both images at 100% and there really is nothing in it. It is hard to see any difference. And that was not exactly what I expected.
I am very pleased that the 18-135 is such a good lens. Comments welcomed.
This is the 18-135 image:
This is the 17-70 image: