Custom functions

Where can I got to get a detailed explaination of the uses for the custom

fuction setting for the 350D and 400D? I'm particularly interested in better

understanding what the term "Back Button Focusing" means. From reading on

other forums I've figured it has it's advantages for shooting fast action--

such as sports-but I just can't seem to find out the details.

 

Thanks,

This is a long shot, but your manual?

 

If back button focus is what I'm thinking it is, Custom Fn 4 on the 20d moves the focus from the shutter button, to the * button on the back of the camera. I use this. I prefer to focus, then use the shutter for exposure setting and taking the pic.

yup, it moves the auto focus function to the * button the back. Its advantage is using it with a full time manual focus lens. That way you can auto focus with the * button, or just manual focus with the ring without having to switch it on the lens, and without it automatically auto focusing when you depress the shutter button.