John Francis wrote: > I've found the AF can actually keep up with cars approaching > head-on at three figure speeds.
Sure. Very low angular velocity of the subject. I don't have any problems with it in those situations. Where it fouls up for me is the "lag time" issue of the area that's in focus when the shutter falls is "behind" the movement of the subject, and the spot that was in focus when I tripped the shutter. > I'd agree with this observation. In general I tend to use the > sensors on the row below center, rather than the middle row. It depends heavily on what I'm doing. In some circumstances lately, I've been intentionally using enough lens, or little enough distance, to get close shots, like the one I described in another message tonight, where you just see the driver and maybe half of the car around him. That's when the point of actual focus in the shot is "behind" the point that was in focus when I closed the shutter release contacts. Also when I'm panning widely and the car is moving past me at high angular velocity. > In fact a year > or two ago I was shooting with the 1.7x AF adapter on my 300/f2.8, > which restricts me to just the central AF point, and that combination > didn't work all that well with the head-on shots of cars cresting a > hill. The next day I went back with the FA 250-600 and got a much > higher hit rate shooting from exactly the same point. How "frame filling" were the cars? I'm guessing "very", so there was a good bit of movement during the button-press-to-image cycle. > I'm not sure that the Pentax SR system will work at all when panning; > it only appears to have on/off settings, not a vertical-only mode. I'm hoping. Regardless of what the manual says, that's one of the first things I'll be testing. ;-) -- Thanks, DougF (KG4LMZ) -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
