diff --git a/src/pyronn_torch/conebeam.py b/src/pyronn_torch/conebeam.py
index 32f126f431f325ab5076621db0561da8c9b84020..278d2a5b54c265583a8bee08b2556b882682b2ea 100644
--- a/src/pyronn_torch/conebeam.py
+++ b/src/pyronn_torch/conebeam.py
@@ -163,7 +163,7 @@ class ConeBeamProjector:
             tuple(map(torch.from_numpy, inv_matrices))).cuda().contiguous()
         self._source_points = torch.stack(
             tuple(map(torch.from_numpy, source_points))).cuda().contiguous()
-        self._projection_multiplier = 1.
+        self._projection_multiplier = 1. / self._projection_matrices.shape[0]
 
     @property
     def projection_matrices(self):