The high performance optical construction of 21 elements in 14 groups includes five ED lenses and one Super ED lens to help reduce chromatic aberration that often occurs in telephoto lenses. As a result, it delivers the highest image quality in its class. The lens has been designed for handheld shooting with a 5.0-stop* image stabilisation system and weighs less than 1.4kg. The linear motor realises fast autofocusing and makes it perfect for shooting fast-moving subjects including aircraft and motorsports. The lens is also both water and dust resistant and can operate in temperatures as low as -10°C, so it is suitable for use in a wide range of outdoor shooting conditions. A fluorine coating has also been applied to the front lens element to repel water and dirt, further improving the toughness of the lens.