[COMPATIBLE CAMERA MODEL] The zoom range is 420mm-800mm and the maximum aperture in the zoom range is f/8.3-16, which greatly expands the camera's perspective and allows the photographer to shoot professional shots from considerable distances.T2 mount supports adapter ring to for for for Minolta, for for Pentax, for and other DSLR cameras. [USING METHOD] Screw the lens onto the adapter ring and connect to the camera body when shooting. The camera dial is set to M manual mode, can change the exposure through shutter speed or ISO. Some camera can realize automatically expose, and use AV mode shooting depending on the camera's functions. [FAR DISTANCE PHOTOGRAPHY] 420-800mm Zoom Telephoto Zoom Lens Aperture F/8.3-16 For SLR Camera Far Distance Photography .Suitable for shooting subjects that photographers cannot get close to (such as sports matches, wild animals, long-distance close-up, etc.) [ALL MANUAL FOCUS] Wide and comfortable focus ring, even and soft damping, remarkable feel.Support full manual mode and aperture priority mode linkage metering.The lens optical properties eliminate glare and reduce aberrations, resulting in a clear and bright lens each time. [APERTURE] Multilayer MC coating on optical glass.Tripod ring lock for external tripod system.The aperture changes with the focal length, no aperture adjustment ring, the aperture cannot be adjusted under fixed focal length.