My very first fixed focal length (prime) lens was an EF50mm f/1.8 II. But when I needed faster focusing, I knew I had to replace it with the EF50mm f/1.2 L USM. At maximum aperture of f/1.2, no other brand of lenses come close to its brightness. Together with the EF 85mm f/1.2 L II USM, these are the pride of Canon's superb wide-aperture lenses.