The Sigma1.4x DG EX APO Tele Converterfor Canon (also known as a tele-extender) will multiply the focal length of the existing lens by 1.4x, and will cut back the amount of light by one f/stop. For example, using a 1.4x teleconverter with a 300 mm lens will effectively increase the focal length to 420mm. A lens set to f/2.8 will now be f/4.
Note: Sigma APO Tele Converter 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. Please click here for acompatibility chart of all compatible lenses.
The DG denotes an added coating that achieves the best color balance while cutting down on ghosting caused by reflections from the digital image sensor.