diff --git a/odak/learn/wave/classical.py b/odak/learn/wave/classical.py
index bba42146..13d50b64 100644
--- a/odak/learn/wave/classical.py
+++ b/odak/learn/wave/classical.py
@@ -223,7 +223,7 @@ def get_transfer_function_fresnel_kernel(nu, nv, dx = 8e-6, wavelength = 515e-9,
     fy = torch.linspace(-1. / 2. /dx, 1. / 2. /dx, nv, dtype = torch.float32, device = device)
     FY, FX = torch.meshgrid(fx, fy, indexing = 'ij')
     k = wavenumber(wavelength)
-    H = torch.exp(1j* k * distance * (1 - (FX * wavelength) ** 2 - (FY * wavelength) ** 2) ** 0.5).to(device)
+    H = torch.exp(1j*distance* (k- torch.pi *wavelength*(FX**2 + FY**2)))
     return H
 
 
diff --git a/test/test_learn_wave_propagate_beam.py b/test/test_learn_wave_propagate_beam.py
index 3b1ce19d..0c7f244d 100644
--- a/test/test_learn_wave_propagate_beam.py
+++ b/test/test_learn_wave_propagate_beam.py
@@ -9,41 +9,41 @@ def test():
     wavelength = 532e-9 # (1)
     pixel_pitch = 8e-6 # (2)
     distance = 0.5e-2 # (3)
-    propagation_type = 'Bandlimited Angular Spectrum' # (4)
+    propagation_types = ['Angular Spectrum', 'Transfer Function Fresnel'] # (4)
     k = odak.learn.wave.wavenumber(wavelength) # (5)
 
-
+    
     amplitude = torch.zeros(500, 500)
     amplitude[200:300, 200:300 ] = 1. # (5)
     phase = torch.randn_like(amplitude) * 2 * odak.pi # (6)
     hologram = odak.learn.wave.generate_complex_field(amplitude, phase) # (7)
 
-
-    image_plane = odak.learn.wave.propagate_beam(
-                                                 hologram,
-                                                 k,
-                                                 distance,
-                                                 pixel_pitch,
-                                                 wavelength,
-                                                 propagation_type,
-                                                 zero_padding = [True, False, True] # (8)
-                                                ) # (9)
-
-    image_intensity = odak.learn.wave.calculate_amplitude(image_plane) ** 2 # (10)
-    hologram_intensity = amplitude ** 2
-
-    odak.learn.tools.save_image(
-                                'image_intensity.png', 
-                                image_intensity, 
-                                cmin = 0., 
-                                cmax = 1.
-                               ) # (11)
-    odak.learn.tools.save_image(
-                                'hologram_intensity.png', 
-                                hologram_intensity, 
-                                cmin = 0., 
-                                cmax = 1.
-                               ) # (12)
+    for propagation_type in propagation_types:
+        image_plane = odak.learn.wave.propagate_beam(
+                                                    hologram,
+                                                    k,
+                                                    distance,
+                                                    pixel_pitch,
+                                                    wavelength,
+                                                    propagation_type,
+                                                    zero_padding = [True, False, True] # (8)
+                                                    ) # (9)
+
+        image_intensity = odak.learn.wave.calculate_amplitude(image_plane) ** 2 # (10)
+        hologram_intensity = amplitude ** 2
+
+        odak.learn.tools.save_image(
+                                    'image_intensity_'+'{}.png'.format(propagation_type.replace(' ', '_')), 
+                                    image_intensity, 
+                                    cmin = 0., 
+                                    cmax = 1.
+                                ) # (11)
+        odak.learn.tools.save_image(
+                                    'hologram_intensity_'+'{}.png'.format(propagation_type.replace(' ', '_')), 
+                                    hologram_intensity, 
+                                    cmin = 0., 
+                                    cmax = 1.
+                                ) # (12)
     assert True == True