Quote Originally Posted by Björn Benckert View Post
Just saying a speedbooster does nothing but turning your lens into a wider faster lens with smaller image circle.
I think the only real argument by cinematographers has been that the lenses are not designed to have speedboosters put on them and by showing too much of the image circle you see the softness of the edges and add CA... etc

it's just a cheat... like lots of stuff you do in film... sometimes you can get away with cheating, sometimes you can't

anamorphic is basically a cheat, you have 4-perf film and you wanted widescreen, you could just crop the film, or use optics to squeeze the image onto a 4/3 film plane