But those are cinematography lenses--they cast image circles that are significantly smaller than what is needed for a 36x24mm sensor. And even then, with the smaller format requirement, the 150/1.2 weighs 8.8 pounds! I think it's safe to say that if Canon ever made such a design for a full-frame 35mm camera, and included USM and IS, it would weigh a lot more....


It's easier to design lenses for smaller formats. You need less glass; more specifically, you can get away with smaller glass.