After making my own NEX Focusing Helicoid, I dug out some projection lenses I have collected and tried them on. The Kern-Paillard 50mm f1.3 projection lens stood out and struck me with its sharpness wide open. Like most short projection lenses, this one has a very short lens to film plane distance, making it almost impossible to be used on most DSLRs. I was able to make a lens out of it using the helicoid I made, but even with the NEX, the lens is very close to the sensor. Of course, projection lenses do not have apertures. I took a few shots around the house and I am very impressed with the lens. It's bitingly sharp at full aperture. I can't imagine how much sharp the lens will be by stopping down just a little. Unfortunately, I will probably never be able to find out. Even as the way it is, this lens can make some wonderful images. I am sure I will use it more in the future.