This lens is part of a FULL SET OF 14 Lenses. This is the fastest 85mm lens currently available in the market and essentially a FD 85mm f1.2 'L' lens at its infantry stage (the equivalent Canon 85mm f/1.2L was probably introduced in 1980) . As the latest success in Canon's revolutionary development of the aspherical lens concept, this lens occupies a particularly high respect among the lens manufacturing community. The incorporation of an aspherical element in its design results in the virtual elimination of flare, from a bright f/1.2 to a stopped-down f/16. Especially at full aperture opening, sharpness and contrast to the picture is remarkable compared to spherical lenses. The exclusive Canon Floating System ensures high performance even at the close focusing distance. Along with the elimination of flare at the maximum lens opening, equal effort was placed with successful results in producing fine resolution of image at smaller apertures during daytime photography. This lens has been amazingly REMOUNTED to EF, DECLICKED AND with a CUSTOM LENS CAP from Ron Sim of Simmod, in Indiana. The lens's FOCUS, and IRIS have been GEARED by the very Sean McCurry at Follow Focus Gears in Georgia... **Who, for the first time ever, learned how to ENGRAVE F-STOP MARKINGS. He did this, for the first time into every one of these lens's iris rings and matched them appropriately to their LIGHT MEASUREMENTS. Way to go above and beyond, Cap'n. The iris turns past F16, F22 or F32 on all of the lenses, in this set, except the 50mm f3.5, 55mm f1.2 and the 135mm f2.0. Be careful when turning not to turn it past that point, otherwise it won't be adjusting exposure, accordingly. Ron Sim informed me that those connecting the iris to a follow focus should be careful. This is because the iris turns past it's "most closed" point on most of these lenses. My advice is, if you do connect the iris to a follow focus, you will need to manually calibrate the follow focus to know that the end of the iris is where it is, and not where the lens turns to. That would tear at the iris ring. So the iris ring is for reference and the knowledgeably careful. Turning the whole iris turn on a follow focus is bad for the lens and it isn't good to have that part in the focus puller's calibration either. So please leave that part of the iris turn for all practical purposes. These lenses all have 77MM INNER DIAMTERS and 80MM OUTER DIAMTETERS. So you can easily attach and swap 77mm variable nd filters between these lenses and you can attach an attachable mattebox such as the Misfit Atom to all of these lenses.