The Vivitar 2x 7-Elements Teleconverter for Nikon cameras is a precision optical component designed to expand your photographic capabilities. This premium quality 2x teleconverter, effectively doubles the focal length of the lens it's used with and maintains the resolution and contrast of any fine optic. A 7-elements teleconverter will deliver sharper images with more depth compared to teleconverters with fewer elements.The 2x teleconverter extender will multiply the focal length of the existing lens by 2x, and will cut back the amount of light by 2 f/stops. For example, using a 2x teleconverter with a 300mm lens will effectively increase the focal length to 600mm. A lens set to f/2.8 will now be f/5.6.
Use with NIKKOR lenses that are f/2.8 or faster is recommended. Because use of a 2x teleconverter incurs a 2-stop light-loss, the camera's autofocus system may not function correctly; manual focus would still be available in this situation. This teleconverter will maintain aperture control, manual/auto/program/etc., with all AF-AFS autofocus NIKKOR lenses.