The Sigma APO Teleconverter 2x EX DG (also known as a tele-extender) will multiply the focal length 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 300 mm lens will effectively increase the focal length to 600 mm. A lens set to f/2.8 will now be f/5.6.
Note: Sigma APO Teleconverter 1.4x and 2x are dedicated teleconverter lenses. Due to the high optical quality of this teleconverter, this item will only fit and work with a select list of lenses. Sigma recommends using this teleconverter only with their non-HSM type lenses. Please click here for a compatibility chart of all compatible lenses, and note the HSM lenses.
The DG denotes added coating that achieves the best color balance whilst cutting down on ghosting caused by reflections from the digital image sensor.