2. Enables the center AF point to autofocus when the camera is used with Canon EF lens/extender combinations whose combined maximum aperture is f/8. 3. Improves the speed of the camera's acquisition of focus when using a Canon Speedlite's AF- assist beam. 4. Fixes a phenomenon in which the LCD monitor may freeze and display Err 70 or Err 80 when a still photo is taken during Live View or in movie shooting mode.