diff --git a/eos/reduction.py b/eos/reduction.py
index 376031e..8e14e67 100644
--- a/eos/reduction.py
+++ b/eos/reduction.py
@@ -344,7 +344,7 @@ class AmorReduction:
         if dataset is None:
             dataset=self.dataset
         proj = LZProjection.from_dataset(dataset, self.grid,
-                                         has_offspecular=(self.experiment_config.incidentAngle==IncidentAngle.alphaF))
+                                         has_offspecular=(self.experiment_config.incidentAngle!=IncidentAngle.alphaF))
 
         if not self.reduction_config.is_default('thetaRangeR'):
             t0 = dataset.geometry.nu - dataset.geometry.mu