Helios 44-M, taken at f2.8 (I think)
It was super easy to do on a Helios 44-2, and since I only paid $25 for the lens, I wasn't too concerned if I messed things up. I also have another Helios 44-2 in much nicer condition that I use as is.Nicely done. I just watched a video about flipping the front lens yesterday and it made me want to buy the lens . Guess I can try it with a few other lenses.