Difficult subjects for AF (Auto Focus) (EOS 70D)

    27-Jun-2013
    8201827700

    Solution

      Autofocus can fail to achieve focus (viewfinder’s focus confirmation light blinks) with certain subjects such as the following:

      • Very low-contrast subjects
        (Example: Blue sky, solid-color walls, etc.)
      • Subjects in very low light
      • Extremely backlit and reflective subjects
        (Example: Car with a highly reflective body, etc.)
      • Near and far subjects covered by an AF point
        (Example: Animal in a cage, etc.)
      • Repetitive patterns
        (Example: Skyscraper windows, computer keyboards, etc.)

      In such cases, do either of the following: 
      • With One-Shot AF, focus an object at the same distance as the subject and lock the focus before recomposing the shot. (For more information refer to the NOTE and Related information sections below.)
      • Set the lens focus mode switch to <MF> and focus manually.


      NOTE
      With [One-Shot AF], while you press the shutter button halfway to focus a still subject, the focus will be locked. You can then recompose the shot and press the shutter button completely to take the picture. This is called "focus lock". For further information, please refer to the Related information section below.
      (In the <> (Sports) mode, AF mode is set to [AI Servo AF] automatically.)