The three choices work like so: One Shot: In this mode, which is geared to shooting stationary subjects, the camera locks focus when you press the shutter button halfway. It also is the most similar to the autofocusing system used for regular viewfinder photography, based on the same nine-point focusing grid. DPR review on T3i page 7/Menus specify this camera to have 3 different AF Modes: Live Mode, Face detection LV and Quick Mode. Live mode autofocusing enables you to set focus on your Canon EOS Rebel T3 or T3i without temporarily losing the monitor preview. I think that resolved the moving target track box. Canon Rebel T3 Series Cameras: Quick Mode Autofocusing in Live View. For more information about the image quality of still images and the recording size of movies, please refer to the instruction manuals that came with your camera. When the movie recording size is [1920×1080 30fps] or when the movie recording size is [1920×1080 24fps] and the [Digital zoom] is set, [Quick mode] cannot be selected. If you point the camera in a different direction, it might throw off the Live View image's correct brightness momentarily. The camera then selects the optimum video output signal (1080/60i, 1080/50i, 480/60p, or 576/50p) and the video is displayed. When focus is achieved, the AF point will turn green and the beeper will sound. Also, achieving focus may be more difficult than with Quick mode. 10x -> Normal view, When the digital zoom is set, press the <. If the camera’s internal temperature increases due to prolonged Live View shooting or a high ambient temperature, a white [, If the camera’s internal temperature further increases while the white [, Shooting with the Live View function at a high temperature for a prolonged period will cause the [. The Canon Rebel T3i's AF lag time in Live View mode was longer than using the optical viewfinder (as expected). You have two choices: Automatic: All nine autofocus points are active, and the camera decides which one to use when setting the focus distance — again, usually selecting the closest object as the focus target. AF during movie shooting is possible with [AF w/ shutter button during video]. Learn how to set the Live View Mode using your Canon Rebel T2i or 550D Website: www.seezmo.com Facebook: https://www.facebook.com/pages/Seezmo/126450740703236 For more information about the [Digital zoom], please refer to the instruction manuals that came with your camera. For more information on how to connect a camera to a TV, please refer to the instruction manuals that came with your camera. Press and hold the shutter button halfway down to focus. [Live mode] is set by default. The dedicated AF sensor is used to focus in the same way as with viewfinder shooting. While looking at the Live View image on the LCD monitor, turn the focusing ring to focus manually. Focusing Using Face Detection Live Mode. Make sure that the camera is ready to take shots, and then press the