diff --git a/hosts/common/programs/v4l-utils.nix b/hosts/common/programs/v4l-utils.nix
index 850d15745..7b073ff9c 100644
--- a/hosts/common/programs/v4l-utils.nix
+++ b/hosts/common/programs/v4l-utils.nix
@@ -5,6 +5,11 @@
 # - `media-ctl -d /dev/media0 --set-v4l2 '"ov5640 3-004c":0[fmt:UYVY8_2X8/1280x720]'`  (doesn't work!)
 # - `ffmpeg -s 1280x720 -f video4linux2 -i /dev/video1 -vframes 1 selfie.jpg`  (doesn't work!)
 # - source: <https://wiki.postmarketos.org/wiki/PINE64_PinePhone_(pine64-pinephone)#Cameras>
+#
+# query layouts:
+# - `v4l2-ctl -d /dev/video1 --all` (front camera?)
+# - `v4l2-ctl -d /dev/video2 --all` (rear camera?)
+# - `v4l2-ctl --list-ctrls-menus -d /dev/video1` (show rotation/flips)
 { pkgs, ... }:
 {
   sane.programs.v4l-utils = {