diff --git a/libeos/__init__.py b/libeos/__init__.py
index f51c189..ed53792 100644
--- a/libeos/__init__.py
+++ b/libeos/__init__.py
@@ -3,4 +3,4 @@ Package to handle data redction at AMOR instrument to be used by eos.py script.
 """
 
 __version__ = '2.1.1'
-__date__    = '2024-08-25'
+__date__    = '2024-10-22'
diff --git a/libeos/reduction.py b/libeos/reduction.py
index 290e921..d064844 100644
--- a/libeos/reduction.py
+++ b/libeos/reduction.py
@@ -439,6 +439,7 @@ class AmorReduction:
             logging.warning('   too small monitor value for normalisation -> ignoring monitors')
         err_lz    = ref_lz * np.sqrt( 1/(int_lz+.1) + 1/norm_lz ) 
 
+        # TODO: allow for non-ideal Delta lambda / lambda (rather than 2.2%)
         res_lz    = np.ones((np.shape(lamda_l[:-1])[0], np.shape(alphaF_z)[0])) * 0.022**2
         res_lz    = res_lz + (0.008/alphaF_lz)**2
         res_lz    = qz_lz * np.sqrt(res_lz)