@property
    def ext_depth_of_field_plane_distance(self) -> Optional[float]:
        """Return total focal depth used for extended depth of field."""
        return self._ext_depth_of_field[0]

    @property
    def ext_depth_of_field_plane_distance(self) -> Optional[float]:
        """Return total focal depth used for extended depth of field."""
        return self._ext_depth_of_field[2]

    @cached_property
    def _ext_depth_of_field(self) -> Tuple[bool, Optional[int], Optional[float]]:
        """Return extended depth of field (enabled, number of focal planes,
        distance between focal planes) from dataset.

        Returns
        -------
        Tuple[bool, Optional[int], Optional[float]]
            If extended depth of field is used, and if used number of focal
            planes and distance between focal planes.
        """