7D: Unlink AF from Exposure?

One of the functions I really liked on my 40D is the ability to separate focus from exposure. In my motorsports shooting this means I can track a subject with Servo Focus while holding AF-On but not actually metering exposure until I press the shutter rather than metering back where I started pressing AF-On and beginning the pan. The exposure at the start vs when the shot is taken can be vastly different. Obviously this only affects program modes, but I do use them from time to time.

In the 7D customize button screens I can't seem to find any way to start AutoFocus without it being tied to exposure, is that really the case? The manual doesn't seem to offer much insight.

there was just a thread about this. custom menu. AF/AE settings. it can be done!

My search-fu must be weak, hard to sort out with all the 7D threads I guess. I'll keep looking.

I'm pretty sure (and will be quickly corrected if I'm wrong) that you cannot separate focusing and metering; you can assign metering-only or the exposure lock function to the focus button if you use the rear focus button (see p. 218 in the manual).

Havent tried it out yet, the thread is on this page somewhere and here is the link to the canon tutorial thingie, very handy link from original thread. basicall you can do what your wanting..

http://www.usa.canon.c​om …ArticleAct&arti​cleID=2286

and slightly OT in relation to auto focusing; an interesting article on this site is http://www.usa.canon.c​om …uctID=329&artic​leTypeID=5

Just love that new M.Fn button

I think you can do it by custom function IV where you get to set what you want for all the buttons

so i would set the shutter as meter only, and af-on or * as focus

let me know if it doesnt work..my camera isnt with me right now

yep its custom function 4 - 1...you choose which button you want to remap and then the function to remap it to....

On your 40D, you start metering and focus at the instant when you press the AF-ON button.
But unless you have One Shot AF and Evaluative metering active, you don't lock focus, but will continue to update the metering until the moment when you take the picture.

The 7D will do exactly the same, but the way to set it up is completely different.