Originally posted by Cambo apparently they have increased the speeds SIGNIFICANTLY, if this post from another forum is true:
"... the AF is far faster in low light...
--
Mike from Canada "
He works at a camera store, and the rep let him try it for quite a while. He aso said it makes the K20D seem slow and clunky in pretty much every performance parameter.
That's MightyMike on these forums, and he already posted similar findings here. We both tried out the K-7 for quite a while at the Pentax Booth at the Imaging Expo here in Toronto this weekend. A bunch of other forum members were there as well and I think we tried almost every lens they had, and compared against both the K-m and the K20D in focus tests. The K-7 could lock on the black-on-black painted beams against the dark exhibition hall ceiling under almost "no light" conditions which my K20D would just hunt forever on. So it is not just *faster* but can lock on things even the demo D300 on the other side of the expo hall (tethered to a table!) simply could not.
However, even with a lot less "hunting" in general, the Pentax SDM lenses weren't any faster on the K-7 (I tried my own 50-135 to be consistent). Compared to Canon L-series USM (a ring motor around the lens focus element), the Pentax SDM (a drive motor in line with the screw shaft) is almost glacial on heavy zooms, so the AF system still has to wait for the elements to moved into the right places. But put a screw-drive DA limited prime on there and *bang* the K-7 is focused almost instantly.
Not sure about the "accuracy" since the SD card doors were quite securely taped shut and the image would only pop up on the (gorgeous) 3" screen for a second... but I'll assume the same as my K20D, which is quite accurate with good glass.