Multi-controller

The EOS cameras that feature a multi-controller (that's the small joystick on the back of the camera) also feature a Custom Function to allow you to use the multi-controller to select an AF point. On the EOS-1D/1Ds Mark III it's available in the latest firmware version and can be accessed using CFn III-09 and then either option 3, 4 or 5. On the EOS 50D and 5D Mark II, it's found in CFn III-3 option 1.

This is a very useful Custom Function to play with as it allows you to quickly select a different focusing point without having to first press the focus point selection button. However, it has a drawback - most notably if you're shooting a lot of shot in portrait orientation. Unless you have abnormally long thumbs, reaching the multi-controller button from the vertical shooting grip is all but impossible and you need to resort to the 'normal' method of AF point selection with the AF point selection button and the main and quick command dial.

It's not a major issue, but is something to be aware of, and for that reason, it might be worth putting that custom function into the My Menu settings on the camera so you can quickly change it as you need to.

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