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.
Large and hefty, at nearly twice the size of comparable Nikon and Pentax f/1.2 manual-focus lenses, this lens exemplifies how the L-series opts for sharpness over compact convenience. The AF speed is somewhat slow, unsurprisingly, given the amount of glass the motor must move. The lens' unusual design shifts the entire optical assembly within a stationary outer housing to focus. To prevent moisture and dust from coming between the assembly and housing, Canon strongly recommends a protective UV filter. Read the whole article here