A Rednote user tried out the Rodenstock TV-Heligon 50mm f/0.75 on the Sony NEX-5:

Recently I dug out my old modified NEX-5 again and tweaked it a bit. Now that I have a 3D printer, adapting things has become much more fun. I currently have two 50mm f/0.75 lenses: the De Oude Delft Rayxar and the Rodenstock TV-Heligon.

In earlier quick tests, I found that the De Oude Delft has a larger image circle (in reality, only the illuminated area is larger—the usable image area isn’t that much bigger), and it also has higher contrast. So I didn’t use the Rodenstock much.

Recently, however, I noticed that the rendering style of these two lenses is actually quite different. The Rodenstock has lower contrast, but the out-of-focus areas are softer and more pleasing.

The sample images are cropped and slightly adjusted in exposure.