Excerpt: This speedy full-frame 50mm f/1.2L ($1,400, street) fills a vacancy left by the demise of Canon's 50mm f/1.0L four years ago. The company's only L-series normal lens, it's the fastest normal AF lens on the planet. Hands On
Conclusion: There’s no doubt that the Canon EF 50mm f/1.2 L USM , ( compare prices ) ( review ) is Canon’s best 50mm lens and an excellent performer by any standard. The fast aperture is ideal for work in low light, where focus is fast and positive.
Summary: Canon EF 50mm f/1.2L USM is a very promising lens - it's one of the fastest prime lenses available for Canon's EF mount and is clearly targeted at photographers who require that extra f-stop and are willing to pay premium for it. However, the lens did not quite live to all my expectations.
Conclusion: EF 50mm f/1.2L USM The superbly built EF 50mm f/1.2L lens provided modestly sharper images with better out of focus blurring (bokeh) at f/1.4 and f/2 and was much more resistant to flare and internal reflections than the EF 50mm f/1.4 lens.