if (!_directory.containsTag(ExifDirectory.TAG_DIGITAL_ZOOM_RATIO)) return null; int equivalentFocalLength = _directory.getInt(ExifDirectory.TAG_DIGITAL_ZOOM_RATIO);
if (!_directory.containsTag(ExifDirectory.TAG_35MM_FILM_EQUIV_FOCAL_LENGTH)) return null; int equivalentFocalLength = _directory.getInt(ExifDirectory.TAG_35MM_FILM_EQUIV_FOCAL_LENGTH);
    public String get35mmFilmEquivFocalLengthDescription() throws MetadataException    {        if (!_directory.containsTag(ExifDirectory.TAG_DIGITAL_ZOOM_RATIO)) return null;        int equivalentFocalLength = _directory.getInt(ExifDirectory.TAG_DIGITAL_ZOOM_RATIO);        if (equivalentFocalLength==0)            return "Unknown";        else            return SimpleDecimalFormatter.format(equivalentFocalLength) + "mm";    }