Excellent optics and superb handling in a compact package, perfect for action and sports. Excellent optics and superb handling in a compact package with Image Stabiliser. The IS allows safe hand-holding at shutter speeds up to two stops slower than otherwise possible, making it even more useful in low light levels. It is less than half the weight of the 300mm f/2.8L IS, and it focuses to an incredibly close 4.9 feet (1.5m), filling the frame with a subject the size of a postcard. Like all of Canon's fixed focal length L-series lenses above 135mm, it's compatible with Canon's EF Extenders 1.4x II and 2x II .