Focus button seperate from shuttter activation?

Well I just upgraded my 50D to a 7D and since there's a bit of a learning curve with the new focus points and all I thought I'd play around with the settings. I was wondering how many people separate their focusing button from the shutter activation button? I've seen references to doing that before but never ventured there. If you do separate them out what is the rational and what do you assign to your focus to? I changed mine to the focus being the AE-L (the * button on the back) and left the front shutter button to be the shutter activation only I know it's different between camera manufacturers but is there a better combination to use?

I need to do this. As for rationale, I think it just makes sense so that you can recompose easier while still having control of the AF. I actually take time to focus on my subject, turn off the AF and recompose sometimes. This would prevent that silliness.

Max

I like having them separate for two reasons... for "focus and recompose" as mentioned, and for "bumping" the focus in cases where the camera is struggling, or flat out missed. What I mean is, I like to be able to hit the focus button to re-focus, rather than half-pressing the shutter button - which is a little easier, and I don't have to worry about accidentally tripping the shutter. I wasn't sure I'd like it at first, but now I'd always look for the ability to do that.

I have an Olympus E-520 and have the focus button assigned to the "Fn" multi-function button the back. The AEL/AFL button is still separate.

Changed my canons after reading about it here about a year ago. Would not change back. Really like having the shutter and focus seperate, also I find it, for me anyway more natural (or something like that). I was always tripping the shutter when I was just trying to focus.

Rationale is as stated above. Allows easy re-composition with a scene. Especially useful, in my view, when shooting with a tripod and a cable or remote release. Once you get focus set, you can change other settings and re-shoot without worrying about whether the focus changes -- especially if you are using a set focus point.

Doesn't work as well, IMO, for "action" shooting. Too many things to remember. Nikons have customizeable "shooting menus" you can set up. I have an "action" menu and my normal menu. The "action" menu has the focus set on the shutter release.

I read about this a few years ago when I bought the 30D and quickly grew to love it. It is one of the first settings I change on a new camera. I assign it to the same button you mentioned and for the same focus/recompose reasoning already given. I even looked for the option on a friends new Rebel series camera but didn't see it. I doubt I could buy a DSLR without the option.

I use the back button for focus as well and I use it for action photography as well where I think it works really well. I've been able to get much better compositions on many action shots by using the back button for focus. On my Canon 1DMark III I switch the AF-ON/AE lock buttons and focus with the AE button because it's easieer to reach the AE button and I trigger with the front shutter button. Using this technique I can recompose the photo by taking my finger off of the focus button and effectively locking the focus. I stay in AI Focus and if the bird takes off I reacquire focus by getting the center AF back on the bird.

The separation has value as indicated. Practice using it before adopting it for an important shoot.

Bill Brennan

Looks like I'm the odd man out here. I tried this several years ago and just wasn't comfortable with it. It's an easy thing to change the settings in the camera but not so easy to reprogram the muscle memory in my hand. My thumb is too busy controlling exposure and AF point location to take on another task. Having the focus actuation on the shutter button is what I'm used to and comfortable with. I have changed other familiar settings settings on occasion when circumstances dictated, but this is one I've never felt the need to change.

Here's another vote for decoupling the AFbutton from the shutter. There's a good reason why Canon allows this option.
Many reasons actually, but the primary one is that I can recompose after activating AF and not worry about any changes when I fire the shutter. This also allows me to lock exposure on a different area with a half press of the shutter and recompose again without worrying about reactivating AF.

I also use AE-L for focus on my Nikon, for all the reasons already mentioned. However, I do find it clumsier when not on a tripod but that's rarely the case for me.

Bill's admonition to practice before adopting for an important shoot is well heeded. Several years back, I read about this "de-coupling" approach in a book by John and Barbara Gerlach and was persuaded that it was a good idea, so I changed my settings. After shooting a small amount, I decided it was a permanent change. I then put the camera away for a period of time. My wife asked me to photograph an event and I arrived, having completely forgotten about the settings change. I couldn't figure out, for the life of me, why my AF "wasn't working." It was just for her and not a paid job, but embarrasing, none the less. It wasn't until I got home later that night, thinking I was going to have to ship the body back to Nikon for service, that I remembered the settings change. Good news is that it has been permanently engraved in my mind since.

Thank you everyone! I've de-coupled the buttons and gotten a few days practice in with it and so far find it really useful. I'm headed down to Florida in a few weeks to do some more intense shooting so we'll see how it works for me then!