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Canon EOS 40D Guide to Digital Photography by David D. Busch

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Custom Function IV (C.Fn. IV): Operation/Others

Within this category of Custom Functions you’ll find seven options for adjusting the behavior of controllers and buttons, specifying the focusing screen in use and other features.

C.Fn IV-01: What Happens when You Partially Depress the Shutter Release/Press the AE Lock Button

Shutter button/AF-ON button

This setting controls the behavior of the shutter release and the AF-ON button. In the option list below, the first action in the pair represents what happens when you press the shutter release; the second action says what happens when the AF-ON button is pressed. Note that if you (like many) would prefer to have the 40D meter and focus when the shutter button is pressed halfway, this is not the ...

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