The Canon EF 600mm f/4L IS USM Lens is Canon's longest, almost heaviest (the Canon EF 400mm f/2.8L IS USM Lens is 10g heavier) and almost most expensive (the Canon EF 800mm f/5.6L IS USM Lens costs more) EF lens. It has the reach needed for - and is commonly used for - bird photography, small and distant animal photography, surf photography (from shore), long distance sports photography and many other similar pursuits.
