Opteka 500mm / 1000mm f/6.3 Telephoto Mirror Lens for Canon EOS 1D, 5D, 6D, 7D, 10D, 20D, 30D, 40D, 50D, 60D, Rebel XT, XTi, XS, XSi, T1i, T2i, T3, T3i and T4i Digital SLR Cameras
The Opteka mirror lens is incredibly compact and lightweight. Using an advanced reflex design, this is a mirror lens that is ideally suited for wildlife and sports photography. It has a fixed aperture of f6.3. Opteka mirror lenses incorporates advanced computer designed optics and the latest in multi-coating techniques. The process of multi-coating assures virtually flare free photographs even under adverse lighting conditions resulting in crisp high contrast pictures with full color fidelity.When combined with the T-mount to fit your camera system, this mirror lens mounts to camera and works on both "full frame" cameras as well as the "APS-C" style digital SLR cameras.  T-Mounts are available for all the digital SLR systems, as well as for C-mount systems.  However, in every case the fixed f/6.3 aperture is not communicated to the camera body.  As such, you can use the lens in "M" manual exposure mode or "A" aperture-priority mode only.This lens has a broad diameter and stocky build, making it a bit easier to handle than a normal refractor lens.  It also has a much different rendering of out of focus areas than a normal lens; highlights will be doughnut-shaped rings with more saturation and contrast on the edge of the ring than on the center.SpecificationsFilter Size:95mm front, 34mm rearf/Stop Range:f/6.3 (fixed)Minimum Focus Distance:6.6' (2.0 m)Angle of View:4.1 x 2.7 (WxH)Groups/Elements:6/7Length:4.7" (120mm)Maximum Diameter:3.9" (98mm)Weight:1.55 lbs (705g)Included Items~ Opteka 500mm f/6.3 Telephoto Mirror Lens~ T-Mount Lens Adapter~ Lens Cap~ 10 Year Warranty