Where is the menu for BB focus?

Where is the menu button for bbf? I am on c.Fn 4 Metering start/Meter+AF start. Is this right? Does this lock my focus unless I move off the dof? I do a lot of recomposing and have been missing shots lately... any advice with the bbf?

I use my 40D with Back Button Focus (bbf) but cant remember what custom setting it was under. After you get used to it, you will love it! I had to look in my owner's manual to figure out how to change it... You could look in yours too.

Check this Canon supplied article.

http://www.learn.usa.c​anon.com …ckbutton_af_art​icle.shtml

How to set the camera to focus with the AF-ON button only, but not when half-pressing the trigger button, differs from one camera to the other. It's not only the number of the custom function, but the whole procedure is different between a 40D and a 7D, for example.