diff --git a/workflows/simbox/core/cameras/custom_camera.py b/workflows/simbox/core/cameras/custom_camera.py
index 2b92c66..e427431 100644
--- a/workflows/simbox/core/cameras/custom_camera.py
+++ b/workflows/simbox/core/cameras/custom_camera.py
@@ -32,16 +32,7 @@ class CustomCamera(Camera):
             reference_path: Reference prim path for camera mounting
             name: Camera name
         """
-        # ===== Initialize camera =====
-        super().__init__(
-            prim_path=prim_path,
-            name=name,
-            resolution=(cfg["params"]["resolution_width"], cfg["params"]["resolution_height"]),
-            *args,
-            **kwargs,
-        )
-
-        # ===== From cfg =====
+        # ===== Pre-compute camera parameters =====
         pixel_size = cfg["params"].get("pixel_size")
         f_number = cfg["params"].get("f_number")
         focus_distance = cfg["params"].get("focus_distance")
@@ -50,18 +41,38 @@ class CustomCamera(Camera):
         height = cfg["params"].get("resolution_height")
         self.output_mode = cfg.get("output_mode", "rgb")
 
-        # ===== Compute and set camera parameters (before initialize to avoid aperture mismatch warnings) =====
-        horizontal_aperture = pixel_size * 1e-3 * width
-        vertical_aperture = pixel_size * 1e-3 * height
+        horizontal_aperture = pixel_size * 1e-3 * width / 10.0
+        vertical_aperture = pixel_size * 1e-3 * height / 10.0
         focal_length_x = fx * pixel_size * 1e-3
         focal_length_y = fy * pixel_size * 1e-3
-        focal_length = (focal_length_x + focal_length_y) / 2
+        focal_length = (focal_length_x + focal_length_y) / 2 / 10.0
 
-        self.set_focal_length(focal_length / 10.0)
+        # Pre-set aperture on USD prim before Camera.__init__ to avoid mismatch warnings
+        from pxr import UsdGeom
+        import omni.usd
+        stage = omni.usd.get_context().get_stage()
+        cam_prim = stage.GetPrimAtPath(prim_path)
+        if cam_prim.IsValid():
+            cam = UsdGeom.Camera(cam_prim)
+            cam.GetHorizontalApertureAttr().Set(horizontal_aperture * 10.0)  # USD uses mm
+            cam.GetVerticalApertureAttr().Set(vertical_aperture * 10.0)
+            cam.GetFocalLengthAttr().Set(focal_length * 10.0)
+
+        # ===== Initialize camera =====
+        super().__init__(
+            prim_path=prim_path,
+            name=name,
+            resolution=(width, height),
+            *args,
+            **kwargs,
+        )
+
+        # ===== Set camera parameters =====
+        self.set_focal_length(focal_length)
         self.set_focus_distance(focus_distance)
         self.set_lens_aperture(f_number * 100.0)
-        self.set_horizontal_aperture(horizontal_aperture / 10.0)
-        self.set_vertical_aperture(vertical_aperture / 10.0)
+        self.set_horizontal_aperture(horizontal_aperture)
+        self.set_vertical_aperture(vertical_aperture)
         self.set_clipping_range(0.05, 1.0e5)
         try:
             self.set_lens_distortion_model("pinhole")