Canon EOS Rebel T4i Instruction Manual - Page 294

3 Custom Function SettingsN Custom Functions are organized into four groups based on the function type: C.Fn I: Exposure, C.Fn II: Image, C.Fn III: Autofocus/Drive, C.Fn IV: Operation/Others. C.Fn I: Exposure C.Fn-1 Exposure level increments 0: 1/3-stop 1: 1/2-stop Sets 1/2-stop increments for the shutter speed, aperture, exposure compensation, AEB, flash exposure compensation, etc. This is effective when you prefer to control the exposure in less fine increments than 1/3stop increments. With setting 1, the exposure level will be displayed in the viewfinder and on the LCD monitor as shown below. C.Fn-2 ISO expansion 0: Off 1: On When you set the ISO speed, you will be able to set "H" (equivalent to ISO 25600) for still photos and "H" (equivalent to ISO 12800) for movies. Note that if [C.Fn-3: Highlight tone priority] is set to [1: Enable], "H" cannot be set. 294