Customizing the Fn, Depth-of-Field Preview, and AE-L/AF-L Buttons
You can assign a variety of tasks to the Fn (Function) button and Depth-of-Field Preview buttons, both shown on the left in Figure 10-17, and the AE-L/AF-L button, shown on the right. The next two sections explain your options for still photography and movie recording.
Figure 10-17: You can change the functions performed by these buttons.
Customizing the buttons for still photography
By default, the three buttons are set to perform the following tasks when you're shooting still pictures:
- Fn button: Pressing the button while rotating either command dial toggles the Image Area setting between the FX and DX settings. (Chapter 2 explains this setting.)
- Depth-of-Field Preview button: When you look through the viewfinder and press the button, the display changes to give you an idea of how your current f-stop setting will affect depth of field. If flash is enabled, the flash also emits a modeling flash (a brief burst of flash light to help you preview how your subject will be lit).
- AE-L/AF-L button: Autofocus and autoexposure are locked when you press the button, and they remain locked as long as you keep your finger on the button.
If you don't use the default features very often, you can assign different functions to the buttons. Table 10-1 explains all the possible button settings. Unfortunately, the settings available ...