The opteka 500mm f 8 manual focus lens is a classic refractor-style t-mount lens with an aperture diaphragm in the middle of the lens body to stop down the aperture when necessary. However it is assumed that much of the shooting with such a lens will be at its maximum f 8.0 Aperture with a tripod monopod or other such support. The optional 2x doubler converts this 500mm lens into a 1000mm. When combined with the included t-mount to fit your camera system this super telephoto works on both full frame cameras as well as the aps-c style digital slr cameras. You can use the lens in m manual exposure mode or a aperture-priority mode only. This lens sophisticated achromatic refractor design yields images with pleasing peak contrast and well-controlled flare. It can be used at maximum aperture on a very bright day for some images of moving subjects.
