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

    <desc>Previewing the scene prior to capture using live view mode</desc>
  </info>
  <title>Image preview</title>

  <p>
    The image preview feature gives a live continuously updating view of
    the scene in front of the camera. This requires that the camera supports
    a so called "live view" mode, which is generally true of any DSLR that
    is able to support video recording. This includes all Nikon and Canon
    DSLR cameras manufactured from approximately 2009 onwards.
  </p>

  <p>
    The image preview mode can be activated and deactivated using the
    <guiseq><gui>Camera</gui><gui>Preview</gui></guiseq> menu option,
    the <gui>Preview</gui> toolbar button or by pressing the <key>p</key>
    key. Once activated, the preview mode will remain active until
    it is either explicitly turned off, or until an image is captured.
  </p>

  <p>
    It is possible to request that the preview mode is reactivated
    after capturing by setting a preference. To this, use the
    <guiseq><gui>Edit</gui><gui>Preferences</gui></guiseq> menu
    to open the <gui>Preferences</gui> dialog. Switch to the
    <gui>Capture</gui> page and select the <gui>Continue preview mode after capture</gui>
    checkbox.
  </p>

  <p>
    Preview mode allows for full control over the focus point, not
    activating the autofocus system unless desired. Consult the
    <link xref="camera-focusing"/> section for details on how to control
    focusing manually in preview mode.
  </p>

  <p>
    Normal behaviour when capturing an image in preview mode is to
    trigger the camera's shutter mechanism, which results in a full
    resolution image at the configured quality level. <app>Entangle</app>
    also has support for a simulated electronic shutter though. To
    activate this, use the <guiseq><gui>Edit</gui><gui>Preferences</gui></guiseq> menu
    to open the <gui>Preferences</gui> dialog. Switch to the
    <gui>Capture</gui> page and select the <gui>Use preview output as capture image</gui>
    checkbox. When activated, the next frame of the live preview will be
    saved as the capture image. The preview images are usually in the
    JPEG image format, with a smaller resolution and lower quality compression
    setting - precise details varying according to the camera model.
  </p>
</page>
