The Kenko MC7 AF 2.0X DGX lens is a teleconverter, designed for use with a digital SLR camera like the Nikon F and its lens. The 2.0 converter lens is placed between a digital SLR camera and a separate lens. The optics in the Kenko teleconverter lens for Nikon multiply the focal distance of your lens by a factor of 2.0x, making a 300 mm lens into a 600 mm lens. The autofocus feature on the digital SLR camera works with this 2.0 converter lens if the lens has an open aperture of f/2.8 or larger, adequate light, and contrast. Manual focus is necessary with smaller lens apertures and the Kenko teleconverter lens for Nikon. The Kenko MC7 AF 2.0X DGX features Gate Array Integrated Circuitry to maintain signal integrity. This Kenko converter lens incorporates Hoya multi-coated optical glass. The Kenko MC7 AF 2.0X DGX can multiply any lens collection, increasing long-distance photography options for a professional or dedicated amateur photographer without adding additional lenses to the camera bag.