Few lenses intrigue nature photographers more than super telephotos — 400mm to 600mm lenses with apertures of f/4 or wider. These are serious lenses, both in terms of their size and weight as well as cost. The 500mm and 600mm focal lengths in particular are the favourites of wildlife photographers. But there's little agreement as to which focal length is the preferable choice, and few would or could own both.

Making the wrong purchasing decision can be a costly mistake, and so over the past year as my interest in wildlife photography has broadened I have been pondering which super-tele to purchase. I use Canon equipment, and so my purchase decision was limited to lenses with Canon EF lens mount. But my experience will be relevant as well to someone considering such a lens for the Nikon or other lens mount system.

500mm f/4600mm f/4_______________________________________________________________________

Testing On LocationIf you have never worked with a large-aperture 40...