csaxs_bec/bec_widgets/widgets/tomo_params/tomo_params.py

@@ -2286,7 +2286,7 @@ SETUP_PROFILES: dict[str, dict[str, Any]] = {
         "has_180_mode": False,
         "has_single_point": False,
         "has_zero_deg_reference": True,
-        "fov_fields": [("tomo_circfov", "Circular FOV (µm)", 0.1, 200.0, 2)],
+        "fov_fields": [("tomo_circfov", "Circular FOV (µm, 0 = disabled)", 0.0, 200.0, 2)],
         "stitch_fields": [
             ("lamni_stitch_x", "Stitch x", 0, 50),
             ("lamni_stitch_y", "Stitch y", 0, 50),

csaxs_bec/scans/lamni_fermat_scan.py

@@ -461,8 +461,10 @@ class LamniFermatScan(ScanBase):
             -np.sin(alpha) * stage_x_with_stitch + np.cos(alpha) * stage_y_with_stitch
         )
 
-        # FIXME: We are checking stage_x_rot vs fovy. This needs to be clarified if this is correct
-        # once LamNI is back in operation. We keep it like this for now.
+        # stage_x_rot is checked against fovy (and stage_y_rot against fovx) because alpha
+        # includes a fixed ~90 deg mechanical offset (-300+30.5 deg) between the piezo's
+        # physical axes and the angle=0 sample/beam frame that fovx/fovy are defined in.
+        # So stage_x_rot tracks the beam-frame y-extent, and stage_y_rot the x-extent.
         return (
             np.abs(stage_x_rot) <= (fovy / 2)
             and np.abs(stage_y_rot) <= (fovx / 2)