Originally posted by froeschle So, for a fair comparison, you have to add (at least) the price of the DA* 200/2.8...
Having read the original test, let me explain their rationale...
They wanted every camera to be at 200mm full-frame equivalent focal length (for understandandable reasons), and at f/2.8 for small DoF (for visible out-of-focus, understandable again). And they wanted one lens for all bodies of one maker, to compare bodies, not lenses, within one brand (not affecting Pentax, though, but explaining why they did not choose 135mm with Canon or Nikon). And they preferred a fast (or presumably fast, AF lens).
It was not meant to be a AF price-performance test or even a vendor shoot-out.
For APS-C, they needed a 135mm f/2.8.
So, their choice of the DA* 50-135mm f/2.8 is natural and made them publish the first K20D/SDM AF test by the way as well
They testers themselves considered ALL cameras to be capable to handle the task. This is why I was satisfied for Pentax because with K10D, many would not have thought Pentax could handle the task at all. Well, Pentax came out last but not that much off the pack...
Sony did well in %, but not in absolute numbers of in-focus shots. There, Canon and Nikon excelled. I don't think this is inconsistent with the market beliefs but I don't know for sure.
For speed of lens-AF... Pentax made one photo about every 12m. AT 135mm and distances closer than 30m or so, I guess that the focus had to shift in between shots by considerable amounts (in the end).
Interestingly, a fast fps camera has less focus travel in between shots and a camera not optimized for fast fps must have a problem with AF.C and FAST moving subjects anyway.
Some poster questioned the results. I think they were quite careful. 4 testers in the field, very controlled conditions and 6 repeated series to be on the safe side. They mentioned that D300 delivered inconsistent performance at different tests so I thinh that the others were consistent.
Multi-field AF was said to be worse when the camera still missed the correct focus spot in the first few shots.
I have a question myself:
Why is the DA* 50-135mm slow if it is SDM? I mean, why then make it SDM at all?