KENKO DGX MC7 AF 2x Teleplus converter gives you the dramatic effect of doubling the focal length. KENKO AF Teleplus converters have genuine Gated Array IC. This means that not only the converters own data but all data sent from the camera body provide full exposure metering and electronic flash photography. Auto focus is retained with lens that have a maximum aperture of F/4 or brighter. (Manual focusing will be required with lenses of smaller aperture.)
The 2x DGX Teleconverter (also known as a tele-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 300 mm lens will effectively increase the focal length to 600 mm. A lens set to f/2.8 will now be f/5.6.