How autofocus works..

Hi all,

thought this might be of some use..

http://travel.howstuffworks.com/autofocus3.htm

might get someone a better picture if speed is of the essence..

Also, where it mentions a horizontal sensor strip, on the DSLRs Pentax use horizontal and vertical sensors arranged in crosses (9 per focus point.. I think) to do this.

Cheers

Liam