This high-performance lens was designed with portability and handling ease in mind. One Super UD-glass element, whose characteristics are similar to fluorite, and one UD-glass element result in sharp pictures from corner-to-corner. The lens also has a built-in hood and a detachable tripod mount.
Canon classifies the Canon EF 400mm f/5.6 L USM Lens as a “Super Telephoto” lens. It is super in image and build quality, but is not super in size.
The Canon EF 400mm f/5.6 L USM Lens is relatively light in weight but very solidly built.
If you need the best 400mm image quality available in this price range, the Canon EF 400mm f/5.6 L USM Lens is a great choice – it performs superbly.
The EF 400mm f/5.6 USM L is a very good to excellent lens in all aspects and optically a somewhat superior to the current (locally tested) 400mm alternatives – at least compared to those that are affordable for mortals. So if you can live without IS and search for a very long tele lens for wildlife or sports photography you should have a deeper look at this lens.