Since I have all three at the moment, I decided to make a test for my fellow anamorphic enthusiasts:    http://vimeo.com/60401188   Not exactly scientific, but I tried to be methodical. The Iscorama is sharp wide open, but my Iscomorphot 2x has to be closed down to f/2.8 or smaller, and the Iscomorphot 1.5x really isn't too useful before f/5.6.   They each have their own unique character. Which image do you prefer?