diff --git a/docs/tower-installation.md b/docs/tower-installation.md
index 208182a..edfff4d 100644
--- a/docs/tower-installation.md
+++ b/docs/tower-installation.md
@@ -733,10 +733,12 @@ and the telemetry work. `export_camera_profile.py` picks its `gige` recipe by
 itself when a camera has `ExposureTimeAbs` and no `ExposureTime`: frame trigger
 off (the legacy cameras booted with `TriggerMode = On`, `Line1`), `BayerRG8` on
 the colour camera and `Mono8` on a mono one, 60 MB/s each, the frame rate at
-the camera's maximum (rietschen's RGB camera came set to 0.955 fps), and an
-auto-exposure target of 50 %. That last one matters: the keep rule waits for the frame mean
-to reach 50 %, and at the cameras' old 25 every waypoint ran into
-`frame_timeout_ms`.
+the camera's maximum (rietschen's RGB camera came set to 0.955 fps), and
+auto-exposure on the frame mean (`ExposureAutoAlg = Mean`) at 50 % +- 5 %, down
+to 20 us by day. That last one matters: the keep rule waits for the frame mean
+to reach 50 % +- 5 %. At the cameras' old target of 25 every waypoint ran into
+`frame_timeout_ms`, and so it did with the RGB camera's `FitRange` and 10 %
+tolerance, which fit the histogram wherever its mean lands.
 
 Give `--camera` the id: with several cameras the first one the SDK lists is
 not the colour one, and the order changes from run to run. `install.sh
diff --git a/scripts/export_camera_profile.py b/scripts/export_camera_profile.py
index 58a8d9e..2b972b4 100755
--- a/scripts/export_camera_profile.py
+++ b/scripts/export_camera_profile.py
@@ -154,6 +154,11 @@ _GIGE_COMMON = [
     # The keep rule waits for the frame mean to reach the camera's target. The
     # host starts on its default band of 50 % - rietschen's cameras were set to
     # 25, and every waypoint then ran into frame_timeout_ms (7.5 s, 2026-10-20).
+    # The camera has to aim at the mean, and stop adjusting only inside the same
+    # +-5 %: the RGB camera came with FitRange (which fits the histogram, wherever
+    # the mean lands) and a 10 % tolerance, and no waypoint settled (2026-10-21).
+    ("ExposureAutoAlg",            "Mean"),
+    ("ExposureAutoAdjustTol",      5),
     ("ExposureAutoTarget",         50),
     ("ExposureAuto",               "Continuous"),
     ("GainAuto",                   "Continuous"),
@@ -162,7 +167,10 @@ _GIGE_COMMON = [
 GIGE_RECIPES = {
     "standard": _GIGE_COMMON + [
         ("ExposureAutoMax",            20000),
-        ("ExposureAutoMin",            200),
+        # Rietschen's RGB camera sat at 200-600 us at noon: a floor of 200 left it
+        # no room to darken a bright view, and without chunk data the host cannot
+        # tell a camera at its limit from one still settling. The Manta goes to 16.
+        ("ExposureAutoMin",            20),
         ("GainAutoMax",                24.0),
     ],
     "night": _GIGE_COMMON + [