diff --git a/picamera_coverage.zip b/picamera_coverage.zip
index b30b7cb0..524b4044 100644
Binary files a/picamera_coverage.zip and b/picamera_coverage.zip differ
diff --git a/src/openflexure_microscope_server/things/camera/picamera.py b/src/openflexure_microscope_server/things/camera/picamera.py
index a759ab02..40ad6bda 100644
--- a/src/openflexure_microscope_server/things/camera/picamera.py
+++ b/src/openflexure_microscope_server/things/camera/picamera.py
@@ -719,8 +719,8 @@ class StreamingPiCamera2(BaseCamera):
         )
 
     @lt.property
-    def gamma_correction(self) -> float:
-        """Return the gamma correction from the tuning file."""
+    def gamma_correction(self) -> list[int]:
+        """Return the gamma correction curve from the tuning file."""
         return tf_utils.get_gamma_curve(self.tuning)
 
     @lt.action
diff --git a/src/openflexure_microscope_server/things/camera/picamera_tuning_file_utils.py b/src/openflexure_microscope_server/things/camera/picamera_tuning_file_utils.py
index 29729741..f83a82c4 100644
--- a/src/openflexure_microscope_server/things/camera/picamera_tuning_file_utils.py
+++ b/src/openflexure_microscope_server/things/camera/picamera_tuning_file_utils.py
@@ -186,24 +186,24 @@ def get_lst(tuning: dict) -> LensShadingModel:
     )
 
 
-def get_gamma_curve(tuning: dict) -> dict[int, float]:
+def get_gamma_curve(tuning: dict) -> list[int]:
     """Return the gamma curve from the rpi.contrast section of the tuning file.
 
-    Returns a dictionary mapping input levels to output levels.
-    Defaults to {} if gamma curve is missing.
+    Returns a list where each two elements are the input and output level.
+    Defaults to [] if gamma curve is missing.
     """
     contrast = find_tuning_algo(tuning, "rpi.contrast")
-    return contrast.get("gamma_curve", {})
+    return contrast.get("gamma_curve", [])
 
 
-def set_gamma_curve(tuning: dict, gamma_curve: dict[int, float]) -> dict:
+def set_gamma_curve(tuning: dict, gamma_curve: list[int]) -> dict:
     """Set the gamma curve in the rpi.contrast section of the tuning file.
 
     Returns a new tuning dictionary with the updated gamma curve.
     """
     output_tuning = deepcopy(tuning)
     contrast = find_tuning_algo(output_tuning, "rpi.contrast")
-    contrast["gamma_curve"] = {int(k): float(v) for k, v in gamma_curve.items()}
+    contrast["gamma_curve"] = gamma_curve
     return output_tuning