Summary About two and a half years ago I've purchased a Helios 44M-4 for my Nikon D3200 body. It was my first prime, cheap, but with beautifuly interesting swirly bokeh. Yet the main flaw was that the lens cannot focus to infinity on a Nikon body. I've started modding the lens back then, by replacing the M42 screw mount with a Nikon F adapter. I could get about 2 meters plus focus distance but it wasn't infinity. I also had to create a plastic part that kept pressed the aperture enable lever inside the lens. It was cut out from a CD case and it did a great job. To get infinity focus I had to unscrew the backward lens part (closest to the sensor) by 0,9mm, to let the focus plane aligned with the sensor. Since I got my 3D printer (6 days ago) creating parts is much easier than before. I've measured everything, and modelled the parts that needed, to convert my Helios to a infinity focus lens on a Nikon body. On the attached pictures you can see where you have to place the different parts. The last image is a quick test snaphot with the lens focused to infinity. I didn't attached disassemble images / video because you can find many on Youtube. I've ordered the aluminium Nikon adapter from ebay for about $1. (M42 to Nikon F adapter). Unfortunately I don't know if it works with other Helios 44M models. I hope you find this design useful. Sorry for my bad englis. Print Settings Printer: Anet A8 Rafts: Doesn't Matter Supports: No Resolution: 0.1mm Infill: 30% Notes: Outline shells: 5 I had to use rafts because when I tried without it the first layer couldn't stick to the hotbed even at 215°C. Material: PLA