Canon Telephoto Lenses

It's useful to think of Canon telephoto lenses as telescopes for your film or digital camera. Like a telescope, a telephoto lens enlarges your subject, bringing it closer and making it appear larger in your viewfinder and on your camera's digital sensor.

Telephoto lenses prove invaluable when you can't get near enough to the subject you're photographing. With a telephoto lens you can, for example, take sports shots from the grandstand or shoot pictures of wild animals from the safety of a vehicle or hide.

What are telephoto lenses?

Lenses with a focal length longer than that of a 50mm standard lens can be classed as telephotos. In practice though, 85mm is regarded as the shortest telephoto focal length for fixed or prime lenses, while for telephoto zoom lenses, the short end of the telephoto range starts around 70mm, as in a Canon 70-200mm telephoto zoom.

Telephoto Lens Magnification

The longer the focal length of a lens, the greater the magnification. Thus a 100mm telephoto lens gives twice the magnification of a 50mm standard lens. In practice, this means the subject's height and width in the viewfinder - and hence on the digital sensor or film - is doubled when you attach a 100mm lens to the camera. Similarly, a 400mm telephoto lens gives eight times (x8) the magnification of a standard lens.

If you're on safari and there's a big male lion staring at you from 50m away, he's going to appear very small in the viewfinder with a 50mm lens on the camera. Change that to a 500mm telephoto lens, and the lion is magnified 10 times. Now he nearly fills the frame and you can even see the scars on his face and the piercing yellow eyes.

Prime v Zoom Telephoto Lenses

Canon telephoto lenses fall into two main categories:
1. Fixed focal length, or prime, telephotos
2. Zoom telephotos that offer variable focal length

1. Prime telephotos offer the best image quality because they have fewer lens elements, so fewer compromises have to be made. Their main disadvantage is the fixed focal length, limiting your options when composing the shot. When photographing fast moving subjects, as in sport or wildlife, you can find the subject suddenly looming too large in the viewfinder. These lenses are also large, heavy, and expensive.

They are nevertheless the first choice for professional sports and wildlife photographers because the quality can't be beaten and they offer wider maximum apertures than zoom lenses of equivalent focal length.

Within the family of prime Canon telephoto lenses, some of the most prized are:

• Canon EF 600mm f/4.0L IS USM lens -- for wildlife and sports such as surfing and cricket where this huge lens can be firmly attached to a heavy tripod to keep it steady.
• Canon EF 400mm f/2.8 L IS USM lens -- with it's very fast f2.8 maximum aperture, this lens is a favorite of sports photographers who have to shoot at high speeds under artificial lighting. The f2.8 aperture also isolates the subject, throwing distracting backgrounds out of focus.
• Canon EF 300mm f/2.8L IS USM lens -- brilliant lens for wildlife and sport because of the wide maximum aperture combined with smaller size and weight that makes it easier to use on a monopod, giving the photographer more freedom of movement.
• Canon EF 200mm f/2L IS USM lens -- a high performance lens of shorter focal length but with very wide f2 max aperture that makes it ideal for indoor sports or low light situations such as concerts or theater.

2. Zoom telephotos are hugely popular because of their versatility and often affordable price tag. Lens technology has improved drastically in recent years and today's top-of-the-range Canon zoom lenses compare favorably with Canon's prime lenses when it comes to image quality.

For all-round usefulness, combined with affordability and very acceptable image quality, telephoto zoom lenses are a "must-have" lens for most photographers.

Among the more popular and highly rated Canon telephoto zoom lenses are:

• Canon EF-S 55-250mm f/4-5.6 IS -- compact and affordable, this lens is designed for use with Canon digital SLRs that have the smaller APS-C sensor, such as the Canon Rebels or 40D/50Ds. Good for portraits, plus candid photography, sport, and wildlife in good light.
• Canon EF 70-300mm f/4-5.6 IS USM -- a light lens with surprisingly good image quality for the price. Image stabilization makes it suitable for hand-holding. Good for portraits at the short end, plus sport in good light; also wildlife in good light or when firmly supported in low light.
• Canon EF 70-200mm f/4L USM -- affordable "L" series lens; light, compact and easy to hand hold with superb image quality. Good for travel, wildlife and sports; is available at higher price with image stabilizer.
• Canon EF 100-400mm f/4.5-5.6L IS USM -- big zoom range with image stabilizer; heavy lens with push-pull zoom operation, expensive, but "L" lens quality.

Return to Canon Lens Reports