I have Canon XH A1 and for all events I am using it at 50i mode. In the past three or four days, I went to football playground for championship shooting with camera set on 24F mode. Now that everyone knows, for sports shooting, the cameraman has to pan and tilt the camera in a very rapid motion in order to catch the scene perfectly, but I have noticed that the camera on 24F mode lags in making appropriate focus automatically in very rapid motions. However, when I switch it back to 50i mode, the auto-focus becomes normal. Can anyone explain why there is an issue for focusing in 24F?

Actually, the user manual explicitly mentions this (page 36 of the English language version of the user manual), and it is the same for the autofocus of all camcorders. With a slower frame rate, there are fewer opportunities for the circuitry to analyze the focus so it takes longer. Autofocus systems also have difficulty with low light, dirty windows, surfaces devoid of features, and fast moving objects.

I think that 24F it is not a good choice for documenting sporting events; if you are creating a film and the artistic effect is critical, that's fine, but then this is an entirely different sort of production than event recording.

Thanks for the reply.

With a slower frame rate, there are fewer opportunities for the circuitry to analyze the focus so it takes longer..

That's really interesting. Now that I think about it, this has been my experience as well. I don't use AF very often, but it's definitely slower in 24f. Thanks for the info...guess I need to read my manual a little more thoroughly.