Bower 2x DGII Teleconverter (4 Element) for Sony

Bower's 2x DGII Teleconverter (4 Element) for Sony will effectively double the focal length of your Sony 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 Sony A mount lenses with a maximum aperture greater than f/4.0 in order to fully utilize its autofocus capabilities.