Canon 100-400mm f/4.5-5.6L IS

Canon’s most flexible super zoom has very good sharpness, especially stopped down one stop from wide open. The reasonably light weight and Image Stabilization allow it to be handheld in decent lighting, and the wide zoom range maximizes shooting opportunity without changing lenses. The 100-400 is a ‘telescoping’ (aka push-pull) zoom which takes a little adjustment if you haven’t used one before. Sharp even at 400mm and handheld.

The 100-400 is our second most popular lens—only the 70-200 f/2.8L IS rents more frequently. We have 84 copies in stock but nonetheless we strongly recommend reserving it in advance.

Roger’s Take: This is a compromise lens. It’s not quite as sharp as the 300 and 400mm primes, and has a telescoping zoom which some people don’t like (personally I do, its faster to zoom). The 70-200 f/2.8 is sharper than this lens is from 100-200. But trip after trip I pack up 2 or 3 “best possible” lenses, and then unpack them and put a 100-400 in my bag, because while it is a compromise, it’s a very good compromise. It’s nearly as sharp as the primes (and far sharper than a consumer lens). The huge range means getting the shot framed just right and not having to change lenses, and it’s relatively small and easy to shoot hand-held.