diff --git a/facetracker.py b/facetracker.py
index 0a81423..dc0d552 100644
--- a/facetracker.py
+++ b/facetracker.py
@@ -19,7 +19,7 @@ else:
     parser.add_argument("-W", "--width", type=int, help="Set raw RGB width", default=640)
     parser.add_argument("-H", "--height", type=int, help="Set raw RGB height", default=360)
 if sys.platform == 'linux':
-    parser.add_argument("--dformat", type=str, help="Set which device format to use", default=None)
+    parser.add_argument("--dformat", type=str, help="Set which device format to use (MJPG, YUYV, RGB3, ...)", default=None)
 parser.add_argument("-F", "--fps", type=int, help="Set camera frames per second", default=24)
 parser.add_argument("-c", "--capture", help="Set camera ID (0, 1...) or video file", default="0")
 parser.add_argument("-M", "--mirror-input", action="store_true", help="Process a mirror image of the input video")