The 2x Komura teleconverter (also known as a tele-extender) will multiply the focal Lent 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 150mm lens will effectively increase the focal length to 300 mm. A lens set to f/4 will now be f/8.
Not Compatable with 135mm f/5.6 Macro Bellows Lens