Canon offers more than 70 lenses for EOS cameras.
Below are some examples of photographic situations and suitable lenses. Do remember that the right lens is the one that lets you create the image you want.
It is often difficult to get close to sports competitors or wildlife. A telephoto lens will magnify the subject to help you fill the frame. Canon offers super-telephoto lenses with focal lengths up to 800mm, but these are quite specialist and mostly used by professional photographers. Zoom lenses with focal lengths up to 200mm or 300mm are more flexible and ideal for many subjects.
Enthusiast: EF 70-200mm f/4L IS USM
Budget: 70-300mm f/4-5.6 IS USM
Autumn hedgehog, © Jirí Míchal 2011, Canon EOS-1D Mark II
Lenses with focal lengths between 50mm and 135mm are considered ideal for portraiture - the focal length puts enough distance between the subject and the camera to avoid any perspective distortion of the face, but does not move the photographer too far away.
Ensuring that the background is out-of-focus when shooting a portrait makes the subject stand out. As explained earlier in the tutorial, this is achieved by the narrow depth-of-field of a lens with a large maximum aperture.
Enthusiast: EF 85mm f/1.8 USM
Budget: EF 50mm f/1.4 USM
Man of Crete, © Marcel van der Velden 2011, Canon EOS 40D
Many photographers like to shoot landscapes with a wide-angle lens, taking in a wide expanse of the scene. A large maximum aperture is less important, as landscapes are usually taken with a small aperture to give a depth-of-field that extends from the foreground to the horizon.
Enthusiast: EF 24mm f/2.8 IS USM
Budget: EF-S 10-22mm f/3.5-4.5 USM
Only dreamed, © André Egli 2012, Canon EOS D60
Magnified images of a small subject can be both educational and entertaining. A macro lens has extended focusing that takes you in close enough to create life-size images of subjects. The lens is optimised to give the best performance at these close distances, though focusing to infinity is also possible. This makes macro lenses very versatile.
Enthusiast: EF 100mm f/2.8L IS Macro USM
Budget: EF-S 60mm f/2.8 Macro USM
Ladybird, © O.Exel 2012, Canon EOS 500D