BlueTech 650-1300mm f/8-16 Manual Focus Telephoto Zoom Lens (Black) + 2x Teleconverter = 2600mm For Sony Alpha SLT, A33, A35, A37, SLT-A55, A57, SLT-A57M, A57K, A58, A58, A58K, A65, A65V, A65VL, A77, A77, A77II, A99, A99V, A100, A200, A230, A290, A300, A330, A350, A380, A390, A450, A500, A560, A550, A580, A700, A850, A900 (A-Mount) Digital SLR Cameras

This extreme: 650-1300mm f/8-16 Manual Focus Lens is an economical way to achieve some ultra-telephoto photography, all the way up to 1300mm----This is a T-mount lens, which means that aperture is not communicated to or controlled by the camera body, and as such must be used only in aperture-priority autoexposure mode (if your camera has it) or in the manual exposure mode -----It will work on both "full frame" digital cameras as well as the smaller-format APS-C (15 x 22mm) cameras, but has only one effective aperture at any focal length, which varies from f/8.0 at 650mm to f/16.0 at 1300mm. That's not much of a hindrance, however, as you'd likely use this lens at its relatively small maximum aperture in any case. This lens requires bright light and a high ISO setting on the camera to get a fast shutter speed (or fast film in a film camera), and needs a sturdy tripod or monopod, but can deliver very sharp results if used properly.-----The lens features an incredible zoom range.-----This lens has a two-touch zoom/focusing system.-----There is a push-pull ring for zooming, and another ring for focusing.-----Multi-coated elements reduce flare and increase light transmission. -----The aperture is fixed-position, but only varies based on focal length. ----The lens has a tripod mount upon its lens barrel.