Originally posted by Burgerbrater Hey Ash,
However I shot the same Image again that I did with the Sigma 18-50mm ex and I can tell you so far there is no comparisen. The lesne is 30 percent sharper in the middle, higher contrast. Its like putting on glasses when you know that your eyes are getting bad. Also the manual focus is very very good. Smooth and precise. However I will have to do more tests before I conclude. After all I dont want decentration again.
so long,
Alex
I'll have to disagree with you on that one. The Pentax has some advantages over the Sigma 18-50 but sharpness and contrast are not two of them. I would have liked the 16mm focal length and weather sealing, but I bought three Pentaxes and all were decentered. The Pentaxes also had much higher CA and purple fringing.
I hope you got a good Pentax. I tested the 16-50s by shooting a lens chart against a wall. It is very important to get the lens axis exactly perpendicular to the wall. I did this by putting a mirror in the middle of the chart and adjusting my camera position until the reflection of the lens was in the exact center of the mirror. I tested my setup with known good lenses to be sure that I did not have anything misaligned.