The Samyang 500mm f6.3 DX is a reflex mirror lens for Full Frame or APS-C size sensor cameras, with a universal T-Mount. This type of lens construction creates a high magnification lens with a short overall length and the f6.3 fixed aperture is a half stop faster than is typical for this focal length. The T-mount must be purchased separately and simply screws on the rear of the lens, so if you change camera it’s easy to convert the lens for a modest price. For best results use with a tripod. Carrying bag included.