Our reader Espen modified the Rodenstock TV-Heligon 50mm f/0.75 (on eBay here) so that it fits natively on the Sony E-mount cameras. He writes:
A month back I posted in this group about a new lens I was modifying for use on my Sony A7RII. The Rodenstock TV-Heligon 50mm f/0.75. There was people who were intrigued and wanted an update when it was done, and some very skeptical of the lens capabilities. No wonder some are skeptical of X-ray lenses (yes I know it’s not really an X-ray lens) in general, because the internet is flooded with fuzzy unsharp close-up shots, when people are using these types of lenses. Don’t think these were designed to do macro shots. Anyways here are the results of the three first test runs of my most light sensitive lens in my arsenal, on my trusted Sony A7RII. First off, it ain’t sharp by modern standards, but I don’t think anybody expected it to be. Weird thing is, it gets sharper the closer you come to infinity focus. Another thing to note, the image circle cover barely APS-C at portrait distance, and it almost touches the outer sensor filters, so it is kinda sketchy to use. I think I definitely am pushing my Sony A7RII to the limit with this one, but this camera series is one of the few that can actually use the lens effectively, to its full potential.
If you want to see the rest of the usable photos I captured and some more information on the lens, please visit this website (work in progress): https://espensusort.no/2021/03/rodenstock-50mm-f-0-75-4/
Here are a few images samples: