The Canon Extender EF 2x III is specially designed for the super telephoto lenses of the professional L-series from Canon. You do not only see this on the outside. This extender has also received the same careful internal treatment as the lenses from this series. Photojournalists, nature and sports photographers can easily expand their collection of beautiful lenses with a 2x extension of the focal length. The unlocking mechanism has been placed with care, making the extender quick and easy to assemble. Your lens is not exposed to all the misery from outside for too long. In addition, the Canon Extender EF 2x III, like all professional Canon products, is resistant to dust and moisture.
You'll get even more similarities with the L- to encounter lenses. The Canon Extender EF 2x III has seven lens elements in three groups. Each of these elements is equipped with Canon's Super Spectra coating to prevent reflections and flare. In addition, the front and rear elements are provided with a fluorine coating, making dust, moisture and stains easily removable. The communication between lens and camera body also continues thanks to the built-in processor. All focus, light metering and ID information is transmitted quickly, so you always use the right information.
Note: When using this extender you lose 2 stops of light. That means that you go from aperture f / 4 to f / 8, for example. When the aperture of the lens becomes f / 8 or more when using an extender, only the manual focus can be used.