Canon EOS Rebel T3 18-55mm IS II Lens Kit EOS REBEL T3 / EOS 1100D Instruction - Page 221

3 Custom Function SettingsN 2: Enable external flash only If an external Speedlite is attached, it will emit the AF-assist beam when necessary. The camera's built-in flash will not fire the AF-assist beam. 3: IR AF assist beam only Among external Speedlites, only those which have an infrared AF-assist beam will be able to emit the beam. This prevents any Speedlite which uses a series of small flashes (like the built-in flash) from firing the AFassist beam. With an EX-series Speedlite equipped with a LED light, the LED light will not automatically turn on for AF-assist. If the external Speedlite's [AF-assist beam firing] Custom Function is set to [Disabled], the Speedlite will not emit the AF-assist beam even if the camera's C.Fn-6 is set to 0, 2, or 3. C.Fn IV: Operation/Others C.Fn-7 Shutter/AE lock button 0: AF/AE lock 1: AE lock/AF Convenient when you want to focus and meter separately. Press the button to autofocus, and press the shutter button halfway to apply AE lock. 2: AF/AF lock, no AE lock In the AI Servo AF mode, you can press the button to stop the AF operation momentarily. This prevents the AF from being thrown off by any obstacle passing between the camera and subject. The exposure is set at the moment the picture is taken. 3: AE/AF, no AE lock This is useful for subjects which keep moving and stopping repeatedly. In the AI Servo AF mode, you can press the button to start or stop the AI Servo AF operation. The exposure is set at the moment the picture is taken. Thus, the optimum focusing and exposure will always be achieved as you wait for the decisive moment. 221