<page xmlns="http://projectmallard.org/1.0/"
      type="topic"
      id="camera-focusing">
  <info>

    <desc>Controlling camera focus during image preview</desc>
  </info>
  Camera Focus

    As mentioned in the  section, no
    attempt is made to activate the autofocus mechanism when capturing
    from preview mode, instead the user has full control over
    focusing via number of keyboard shortcuts.

    To trigger autofocus at any time press the <key>a</key>. If
    the camera is unable to achieve focus, for example, due to
    low lighting conditions or a subject that is too close to
    the lens, an error may be displayed.

    To manually focus, the lens can be moved in either direction
    at two levels of granularity. Small shifts in focal point
    can be made using the <key>,</key> and <key>.</key> keys.
    Moderate shifts in focal point can be made using the
    <key><</key> and <key>></key> keys. If the limit of
    focusing is reached in either direction, an error may be
    displayed.

  <note style="important">
    
      To control focusing from <app>Entangle</app>, the camera body
      and lens must both have their respective
      autofocus switches activated. If either are set to manual
      focus, <app>Entangle</app> will be unable to perform autofocus
      or manual focusing.
    
  </note>
</page>
