Originally posted by Priyantha Bleeker Well just because the AF system and the FPS speed is much better than the current Pentax offerings and it would be very nice to have.
Especialy the faster AF unit would help me a lot with shooting a lot in very low light which I do a lot in disco's at party's.
AF speed is only useful if it works; look at the enormous amount of discussion about the Canon EOS D1 III / EOS D1s III "autofocus disaster" out there. (Sure, it's
fast; accurate is a different problem...)
Me, I think the speed is fine; focus confirmation goes off very quickly when manually focusing, even in dim light. What's not fine is the ability to get a focus lock on a moving subject or a dark on dark (black cat on a dark blue blankie) subject. (The ability to adjust the focus of the lens is mostly dependent on the lens; not, strictly, the problem of the AF module in the camera.)
So I think the AF speed, strictly speaking, in the K20D is fine; what needs work is an actual continuous focus mode (something than cope with the bird feeder swaying back and forth in the wind, say, even if not necessarily with a race car or a downhill skier), first, and secondly, something that can cope with less contrast between subject and background.
Continuous shooting, well, I've never used it. The obvious long-term solution is to build circuitry that can peel raw images off the sensor continuously when the shutter is open; this is a tougher problem but gets away from the mechanical shutter limits. This is the solution Pentax seems to be interested in, given the 21 FPS reduced resolution version in the K20D. Sometime around the K5D I expect we'll be able to fill the card with raw images at about 30 FPS without either melting the sensor or moving the shutter but the once.
Almost all those images will be pretty awful unless the AF is as fast (extremely dubious on simple feedback loop grounds) and the camera is bolted to something really heavy and stable, but the technical capability will be there.