I've heard other people rave about using the back button for focusing. Does it continue to track the focus point after the button isn't pressed? If nothing else I think that would suck the battery pretty fast and get confused when you point it down or elsewhere.
I'll have to mess with it to see how I like it. I could see missing a number of shots at first.
Nope. No battery drain. Here is how you set it up on a Canon 5D II:
- MENU >> far right Camera icon for Custom Settings
- C.Fn IV: Operation/Other Sutter button / AF-ON button (menu choice 1)
- Nav down to 3: AE lock/Metering + AF Start and activate (it will now be highlighted in blue)
- Put camera in IA SERVO mode
- Lens on Auto Focus
Look through viewfinder and place the central focus point on an object to focus on. (assuming that is the one you have set to focus with)
- Press the AF-ON button on the back of camera and central focus mark will flash RED when focus is achieved.
- NOW TAKE YOUR FINGER OFF THE AF-ON BUTTON
- Your focal plain is now set. You can recompose & shoot all day WITHOUT refocusing as long as you or it does not move forward or backward. Sweet
Now lets say things start moving...
- Hold down the AF-ON button and IA SERVO kicks in so you can focus track and fire the subject in focus as long as you continue to hold the AF-ON button down.
You can do this on all of the high end Canons and Nikons but I only know the setting for the 5D.
Hope this helps.