Sigma 2x EX DG APO for Canon (876101) Lens Converter

These are dedicated APO teleconverters that can be mounted between select lenses and the camera body to increase the focal length by the power of 1.4 or 2. They are compatible with the lens autofocus function, depending on the open-aperture F value of the lens being used, and they work with the AE (Automatic Exposure) function, dispensing with complicated exposure calculations. They also offer maximum photography magnification by 1.4 x or 2x, without any variation in the minimum focusing distance. Compact and lightweight, these teleconverters convert your lenses into longer focal-length lenses, so you don't have to do a lot of unnecessary footwork.