03-03-2013 09:17 AM
There are two rings that can be turned on the outside of the lens. The large ring in the middle is for zooming. The smaller ring near the front of the lens is the focusing ring. The focusing ring can be turned all the way to one side for focusing close-up, and all the way to the other side for focusing at infinity. To manually focus at infinity, move the focusing mode switch from AF to MF, then turn the focusing ring all of the way to infinity.
If this is a time sensitive-matter, additional support options are available at Contact Us.
03-03-2013 10:05 AM
Some Canon bodies have AE Lock. Focus on infinity, press AE Lock, recompose your shot and take the picture.
Another way is to focus on infinity, press the shutter button half-way down, hold it. Recompose your shot and press the shutter button all the way.