Bower 2x DGII Teleconverter (4 Element) for Canon SX4DGC

Bower 2x DGII Teleconverter (4 Element) for Canon will effectively double the focal length of your Canon lens, while maintaining the autofocus function. A 50 mm lens becomes a 100 mm lens. The teleconverter uses multi-coated optics to deliver high-quality images. With an 85 mm f/1.4 lens, for example, the focal length will become 170 mm, which effectively sets the maximum aperture at f/2.8 (cutting the amount of light captured by two f/stops). This teleconverter is a portable and versatile accessory that's well worth having in your camera bag. It's only compatible with EF mount lenses with a maximum aperture greater than f/4.0 in order to fully utilize its autofocus capabilities.

Doubles the focal length of a lens