diff --git a/scripts/Diffraction/isis_powder/abstract_inst.py b/scripts/Diffraction/isis_powder/abstract_inst.py
index 0661c6f8a732305e48389006e33bb7cc50448805..4e9a049da257e1735f08de5f0bbdde5cbf458436 100644
--- a/scripts/Diffraction/isis_powder/abstract_inst.py
+++ b/scripts/Diffraction/isis_powder/abstract_inst.py
@@ -231,7 +231,7 @@ class AbstractInst(object):
     def _process_focus_output(self, processed_spectra, run_details, attenuate=False):
         return _empty_hook_return_none()
 
-    def _apply_solid_angle_efficiency_corr(self, ws_to_correct, vanadium_number=None, run_details=None):
+    def apply_solid_angle_efficiency_corr(self, ws_to_correct, vanadium_number=None, run_details=None):
         return ws_to_correct
 
     def _apply_van_calibration_tof_rebinning(self, vanadium_ws, tof_rebin_pass, return_units):
diff --git a/scripts/Diffraction/isis_powder/polaris.py b/scripts/Diffraction/isis_powder/polaris.py
index 9ba46ab7be9ced82972b27c2ef0f712969eb9a11..9bc41770fe4a90315498f360e38b8ba67a3f06c5 100644
--- a/scripts/Diffraction/isis_powder/polaris.py
+++ b/scripts/Diffraction/isis_powder/polaris.py
@@ -21,7 +21,8 @@ class Polaris(AbstractInst):
 
     _number_of_banks = 5
 
-    def __init__(self, user_name, chopper_on, calibration_dir=None, output_dir=None, **kwargs):
+    def __init__(self, user_name, chopper_on, apply_solid_angle=True,
+                 calibration_dir=None, output_dir=None, **kwargs):
 
         super(Polaris, self).__init__(user_name=user_name, calibration_dir=calibration_dir,
                                       output_dir=output_dir, kwargs=kwargs)
@@ -33,10 +34,9 @@ class Polaris(AbstractInst):
         self._run_details_cached_obj = None
 
         # Properties set in later calls:
-        self._apply_solid_angle = None
-
-    def focus(self, run_number, apply_solid_angle=True, do_attenuation=True, do_van_normalisation=True):
         self._apply_solid_angle = apply_solid_angle
+
+    def focus(self, run_number, do_attenuation=True, do_van_normalisation=True):
         return self._focus(run_number=run_number, do_attenuation=do_attenuation,
                            do_van_normalisation=do_van_normalisation)
 
@@ -90,9 +90,8 @@ class Polaris(AbstractInst):
     @staticmethod
     def _generate_inst_file_name(run_number):
         if isinstance(run_number, list):
-            for val in run_number:
-                val = "POL" + str(val)
-            return run_number
+            updated_list = ["POL" + str(val) for val in run_number]
+            return updated_list
         else:
             return "POL" + str(run_number)
 
@@ -125,7 +124,10 @@ class Polaris(AbstractInst):
 
         return corrections_ws
 
-    def _apply_solid_angle_efficiency_corr(self, ws_to_correct, vanadium_number=None, run_details=None):
+    def apply_solid_angle_efficiency_corr(self, ws_to_correct, vanadium_number=None, run_details=None):
+        if not self._apply_solid_angle:
+            return ws_to_correct
+
         assert(vanadium_number or run_details)
 
         if not run_details or not os.path.isfile(run_details.solid_angle_corr):
diff --git a/scripts/Diffraction/isis_powder/routines/calibrate.py b/scripts/Diffraction/isis_powder/routines/calibrate.py
index 4ee32f734b3801008523d376278f8dd8370af974..0a15f79096f9d420884f65bc3bf9d43eb01a9f8a 100644
--- a/scripts/Diffraction/isis_powder/routines/calibrate.py
+++ b/scripts/Diffraction/isis_powder/routines/calibrate.py
@@ -23,8 +23,8 @@ def create_van(instrument, van, empty, output_van_file_name, num_of_splines, abs
     corrected_van_ws = mantid.AlignDetectors(InputWorkspace=corrected_van_ws,
                                              CalibrationFile=run_details.calibration)
 
-    corrected_van_ws = instrument._apply_solid_angle_efficiency_corr(ws_to_correct=corrected_van_ws,
-                                                                     vanadium_number=van)
+    corrected_van_ws = instrument.apply_solid_angle_efficiency_corr(ws_to_correct=corrected_van_ws,
+                                                                    vanadium_number=van)
     if absorb:
         corrected_van_ws = _apply_absorb_corrections(instrument=instrument,
                                                      run_details=run_details,
diff --git a/scripts/Diffraction/isis_powder/routines/focus.py b/scripts/Diffraction/isis_powder/routines/focus.py
index ca0ee09ef946d1849b8be4d099372d3051a93410..4ad5c4ddb9d6f338c77140dc48003d8374050a64 100644
--- a/scripts/Diffraction/isis_powder/routines/focus.py
+++ b/scripts/Diffraction/isis_powder/routines/focus.py
@@ -31,8 +31,8 @@ def _run_focus(instrument, run_number, perform_attenuation, perform_vanadium_nor
     input_workspace = mantid.AlignDetectors(InputWorkspace=input_workspace,
                                             CalibrationFile=run_details.calibration)
 
-    input_workspace = instrument._apply_solid_angle_efficiency_corr(ws_to_correct=input_workspace,
-                                                                    run_details=run_details)
+    input_workspace = instrument.apply_solid_angle_efficiency_corr(ws_to_correct=input_workspace,
+                                                                   run_details=run_details)
 
     focused_ws = mantid.DiffractionFocussing(InputWorkspace=input_workspace,
                                              GroupingFileName=run_details.grouping)