diff --git a/y2023/vision/camera_reader.cc b/y2023/vision/camera_reader.cc
index 7de3eb5..b526086 100644
--- a/y2023/vision/camera_reader.cc
+++ b/y2023/vision/camera_reader.cc
@@ -12,6 +12,7 @@
 
 DEFINE_string(config, "aos_config.json", "Path to the config file to use.");
 DEFINE_bool(lowlight_camera, true, "Switch to use imx462 image sensor.");
+DEFINE_int32(gain, 200, "analogue_gain");
 
 DEFINE_double(red, 1.252, "Red gain");
 DEFINE_double(green, 1, "Green gain");
@@ -117,7 +118,7 @@
                                           rkisp1_selfpath->device(),
                                           camera->device());
   if (FLAGS_lowlight_camera) {
-    v4l2_reader_selfpath.SetGainExt(100);
+    v4l2_reader_selfpath.SetGainExt(FLAGS_gain);
     v4l2_reader_selfpath.SetVerticalBlanking(1000);
     v4l2_reader_selfpath.SetExposure(FLAGS_exposure);
   } else {