TheSchneider Xenon FF 50mm T2.1, Canon EF Mount is part of the Xenon FF set of lenses. FF stands for full frame, and every lens in the set covers a full frame image sensor without vignetting and is designed for 4K image capture. The Xenon FF lenses are color-matched to a standard at the factory, Minimizing colur shift when changing lenses. They feature a 14-blade iris, providing natural looking Bokeh, with circular out of focus highlights, 300° of lens barrel rotation, and share lens gear positions and size.