<!-- -*- xml -*- -->
<page xmlns="http://projectmallard.org/1.0/"
      type="topic"
      id="camera-focusing">
  <info>
    <link type="guide" xref="index#main"/>

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

  <p>
    As mentioned in the <link xref="image-preview"/> section, not
    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.
  </p>

  <p>
    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.
  </p>

  <p>
    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>&lt;</key> and <key>&gt;</key> keys. If the limit of
    focusing is reached in either direction, an error may be
    displayed.
  </p>

  <note style="important">
    <p>
      To control focusing from <app>Entangle</app>, the camera body
      <em>and</em> lens <em>must</em> 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.
    </p>
  </note>
</page>
