The Schneider 09-1078394 Xenon FF 35mm T2.1 Prime Lens in 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 color 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. The lens features a barrel with a large circumference, providing wide spacing for focus marks. Opposing focus scales provide properly oriented focus marks on both sides, so an assistant can pull focus from either side of the lens. Lens gears for focus and iris allow you to use the lens with industry standard lens accessories. The 35mm features a removable lens support bracket, so you can use an available lens support if you wish. The lens is designed to allow a lens technician to swap mounts between available Canon EF, ARRI PL, and Nikon F, avoiding adapters and solidly mounting the lens to your camera. 4K/Full Frame The lenses are designed to cover a full-sized image sensor and provide 4K resolution for image capture. Color Matched The lenses are color matched to a standard ensuring consistent color across lenses. This allows you to purchase lenses, as you need, without having to search through multiple lenses trying to assemble a matched set. Functionality The lenses share the same physical characteristics across the set, this includes the length, diameter, and focus and iris gear position. This speeds up lens changes in the field, minimizing adjustments to matte boxes and lens accessories. Lens Barrel Rotation 300? of lens barrel rotation provides for accurate focus adjustments throughout the range.