diff --git a/cal_tools/cal_tools/agipdlib.py b/cal_tools/cal_tools/agipdlib.py
index ee6367de2abe4c64348d91d8fd9025ece334f6f8..cb4a1ca9891671d372494883b90252ec26492fdb 100644
--- a/cal_tools/cal_tools/agipdlib.py
+++ b/cal_tools/cal_tools/agipdlib.py
@@ -215,6 +215,7 @@ class AgipdCorrections:
         self.mg_hard_threshold = 100
         self.hg_hard_threshold = 100
         self.noisy_adc_threshold = 0.25
+        self.ff_gain = 1
 
         # Shared variables for data and constants
         self.shared_dict = []
@@ -955,15 +956,32 @@ class AgipdCorrections:
         if self.corr_bools.get("xray_corr"):
             bpixels |= cons_data["BadPixelsFF"].astype(np.uint32)[..., :bpixels.shape[2], None]  # noqa
             slopesFF = cons_data["SlopesFF"]
+            # This could be used for backward compatibility
+            # for very old SlopesFF constants
             if len(slopesFF.shape) == 4:
                 slopesFF = slopesFF[..., 0]
-            # Memory cell resolved xray_cor correction
-            xray_cor = slopesFF  # (128, 512, mem_cells)
-
-            # relative X-ray correction is normalized by the median
-            # of all pixels
-
-            xray_cor /= np.nanmedian(xray_cor)
+            # This is for backward compatability for old FF constants
+            # (128, 512, mem_cells)
+            if slopesFF.shape[-1] == 2:
+                xray_cor = np.squeeze(slopesFF[...,0])
+                xray_cor_med = np.nanmedian(xray_cor)
+                xray_cor[np.isnan(xray_cor)]= xray_cor_med
+                xray_cor[(xray_cor<0.8) | (xray_cor>1.2)] = xray_cor_med
+                xray_cor = np.dstack([xray_cor]*self.max_cells)
+            else:
+                # Memory cell resolved xray_cor correction
+                xray_cor = slopesFF  # (128, 512, mem_cells)
+                if xray_cor.shape[-1] < self.max_cells:
+                    # In case of having new constant with less memory cells,
+                    # due to lack of enough FF data or during development.
+                    # xray_cor should be expanded by last memory cell.
+                    xray_cor = np.dstack(xray_cor,
+                                         np.dstack([xray_cor[..., -1]]
+                                            *  (self.max_cells - xray_cor.shape[-1])))  # noqa
+                # This is already done for old constants,
+                # but new constant is absolute and we need to have
+                # global ADU output for the moment
+                xray_cor /= self.ff_gain
 
             self.xray_cor[module_idx][...] = xray_cor.transpose()[...]
 
@@ -1078,22 +1096,6 @@ class AgipdCorrections:
                 # cells are used.
                 with h5py.File(mdata["file-path"], "r") as cf:
                     cons_data[cname] = np.copy(cf[f"{dname}/{cname}/0/data"])
-                    shape = cons_data[cname].shape  # (128, 512, mem_cells)
-                    extra_dims = shape[:2] + (self.max_cells-shape[2], )
-
-                    if extra_dims[-1] != 0 and cname == "BadPixelsFF":
-                        extra_temp = np.zeros(extra_dims, dtype=np.int32)
-                        cons_data[cname] = np.concatenate(
-                            (cons_data[cname], extra_temp), axis=2)
-                        print('An extra dimension was added to the constants '
-                              'for the benefit of BadPixelsFF')
-
-                    if extra_dims[-1] != 0 and cname == "SlopesFF":
-                        extra_temp = np.ones(extra_dims, dtype=np.float32)
-                        cons_data[cname] = np.concatenate(
-                            (cons_data[cname], extra_temp), axis=2)
-                        print('An extra dimension was added to the constants '
-                              'for the benefit of SlopesFF')
             else:
                 # Create empty constant using the list elements
                 cons_data[cname] = getattr(np, mdata["file-path"][0])(mdata["file-path"][1])  # noqa
diff --git a/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb b/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb
index 09b22f1b248153b378723956e7df32ae2987cec4..1ed75fb8c07ee59eda97faa435be60bd38e2dcf1 100644
--- a/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb
+++ b/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb
@@ -63,6 +63,7 @@
     "hg_hard_threshold = 1000 # threshold to force medium gain offset subtracted pixel to high gain\n",
     "mg_hard_threshold = 1000 # threshold to force medium gain offset subtracted pixel from low to medium gain\n",
     "noisy_adc_threshold = 0.25 # threshold to mask complete adc\n",
+    "ff_gain = 7.2 # conversion gain for absolute FlatField constants, while applying xray_gain\n",
     "\n",
     "# Correction Booleans\n",
     "only_offset = False # Apply only Offset correction. if False, Offset is applied by Default. if True, Offset is only applied.\n",
@@ -404,7 +405,8 @@
     "agipd_corr.cm_dark_max = cm_dark_range[1]\n",
     "agipd_corr.cm_dark_fraction = cm_dark_fraction\n",
     "agipd_corr.cm_n_itr = cm_n_itr\n",
-    "agipd_corr.noisy_adc_threshold = noisy_adc_threshold\n"
+    "agipd_corr.noisy_adc_threshold = noisy_adc_threshold\n",
+    "agipd_corr.ff_gain = ff_gain"
    ]
   },
   {