The reversed front element Helios 44 is... weird
The Helios 44, in its many variants, is arguably the single most famous vintage lens. It is a copy of the Carl Zeiss Biotar design, which is a very simple design, consisting in fact of only four pieces of glass, and that makes the lens easy to disassemble to clean and fix, but also makes it easy to modify. The most common mod is to reverse the front element and I was pretty curious to try it myself, so I did. At first results are, well, underwhelming. There is a great loss in image quality and contrast, barrel distortion and blooming are much more prominent and I've found that the minimum focusing distance increases to roughly 1 meter. I soon also noticed that the shape of the boke balls changes based on where you are focusing, close or far, creating distorted yet interesting shapes. When the iris is wide open the image gets so soft that is nearly impossible to focus properly and you have to stop it down quite a bit to get any usable results. ...