Originally posted by kfz How accurate [is] the review??
All such reviews have to be taken with more than a grain or two (or a whole shaker full) of salt. Resolution tests, at best, give only a general indication of the sharpness of a lens. Because of sample variation and tester error, they are rarely consistent from one review to the next. Worse, they only test the resolution at certain lengths (e.g., did they test the resolution at infinity focus?--I didn't think so!) The photozone tests reached slightly different results. They found that the DA 15 tended to be sharper in the center than the DA 12-24 but not as sharp toward the borders. So which lens then is "sharper?" The fact is, in terms of sharpness, there's not any significant difference between the two lenses. I own the DA 12-24, and it's an outstanding lens. But if I needed a 15mm prime, I wouldn't hesitate to get the DA 15; nor should anyone else on the strength, or rather the weakness, of the DPReview's findings.
I also have to protest against any review that compares a pentax lens with a 3rd party lens tested on another camera. Just because the Tokina 12-24 is based on the same optical design as the DA 12-24 doesn't mean that the two lenses will perform identically! The M 50/1.4 and the A 50/1.4 are also based on the same optical design yet the A version
tests out as sharper, especially toward the corners, than the M version. Furthermore, lenses used on cameras from different systems will often lead to different the results. The Tokina 12-24 suffers even more from CA issues on Canon than it does on Nikon cameras, presumably because of the different lens registration lengths of the two systems.