The Nikon TC-14E III teleconverter is a tool that lets you magnify the focal length of Nikkor lenses by 40%. By placing a teleconverter between the body and lens, you can magnify both fast zoom lenses and lenses with a fixed focal length, for a greater range. For example, lenses like the Nikon AF-S 300mm F2.8 G ED VR II are magnified to a focal length of 400 mm, without loss of quality in brightness or image. This allows you to zoom in further for sports or nature photography, for example.