diff --git a/xpcs/src/xpcs/xpcs.py b/xpcs/src/xpcs/xpcs.py
index c7ae062bfc59da40a402797a7900b29a792f925b..cb8cb6aa355783e787fc4919ff16ba419b72bbf8 100644
--- a/xpcs/src/xpcs/xpcs.py
+++ b/xpcs/src/xpcs/xpcs.py
@@ -13,6 +13,8 @@ class Xpcs(BaseCorrectionAddon):
     def __init__(self, config):
         self._ttcdata = TTCdata()
         self._mask_path = config["mask_path"]
+        self._photon_energy = config.get("photonEnergy")
+        
         self._module_no = None
 
         self._current_image_mean = 0
@@ -20,6 +22,7 @@ class Xpcs(BaseCorrectionAddon):
         self._sparse_array = None
         self._cal_mask = None
 
+        
         global cupy
         import cupy
 
@@ -41,6 +44,18 @@ class Xpcs(BaseCorrectionAddon):
             .defaultValue("")
             .reconfigurable()
             .commit(),
+
+
+            # value of the photon energy. used for the photonization step
+            DOUBLE_ELEMENT(schema)
+            .key(f"{prefix}.photonEnergy")
+            .tags("managed")
+            .assignmentOptional()
+            .defaultValue(8.0)
+            .reconfigurable()
+            .commit(),
+        
+
         )
 
     @staticmethod
@@ -72,6 +87,10 @@ class Xpcs(BaseCorrectionAddon):
             self._mask_path = changed_config["mask_path"]
             self.set_mask()
 
+        if changed_config.has("photonEnergy"):
+            self._photon_energy = changed_config["photonEnergy"]
+
+
     def post_correction(self, data, cell_table, pulse_table, output_hash):
         global cupy
 
@@ -79,11 +98,11 @@ class Xpcs(BaseCorrectionAddon):
         data[0] = 0
 
         # Photonize
+        
         # print(f"Unphotonized mean ({data.shape}): {np.nanmean(data)}")
-        start = time.time()
-        data /= 10
-        data[data < 0] = 0
+        data /= self._photon_energy
         np.around(data, out=data)
+
         # print(f"Photonized mean: {np.nanmean(data)}")
 
         # Sparsify