I’ve given this projection lens a page all its own because of its unique characteristics. It started life as a normal projection lens, but I wanted to mount it on my Nikon camera, which has a flange distance such that the lens would not focus to infinity. The lens itself consists of two groups of elements, and so I took the lens apart and tried using only the front group of elements, as this increased the overall focal length of the lens to something around 135mm. It also meant that the aberration corrections of the rear elements were absent, giving the lens a very idiosyncratic character that I really like.
As modified, the lens is only sharp in the center, with what appears to be increasing spherical aberration and strong positive field curvature making the edges soft and somewhat swirly. This is not a lens for all occasions, but it has a strong character and a look all its own.