Originally posted by Lazar 79% doesn't means the 16-45 is bad... it just means that the 18-50mm with 91% is very good according to them.
If the 18-50mm is as sharp (or almost) as the 16-45 and has good contrast, the fact that it has less distortion (according to that review) and a constant f2.8 aperture makes it better (but the 16-45mm is 2mm wider, and at the wide end those 2mm can be very important for some).
Btw, was the Tamron 17-50mm f2.8 also tested? How did it perform?
Yes the Tamron was tested too. It came in joint second with the Nikon/Canon lenses.
Good points were CA was well controlled, ok resolution
Bad points Distortion at wide end and no sonic motor
The performance graph of the Tamron looks much worse than Pentax so its a mystery why it has a high score. The problem is that they don't mention what the graphs measure.
I dont believe the Tamron comes in a Pentax mount unless you've heard otherwise....