The Vivitar 2x 7-element 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-element teleconverter will deliver sharper images with more depth compared to teleconverters with fewer elements. Light will be reduced by 2 f/stops with this teleconverter. For example, a 300mm lens will doubled to 600mm and an aperture of f/2.8 will be reduced to f/5.6.
