Lens focal lengths

Choose the right lens for the job

Techniques

06 October 2008 12:29

Lens Choice

Lenses have an obvious affect on composition - the shorter the focal length, the wider the view; the longer the focal length, the narrower the view. But this is only part of the story when it comes to composition. The other (and in many ways more powerful) tool you have to hand, is the ability to use your viewpoint and lens choice to alter the perspective of your images. Using a wide-angle lens from close to the subject will make the background appear further away. But use a longer lens from further away, and the distance between the subject and background appears to become compressed.

Wide 18mm

Shooting from close to the model has made the background appear much smaller in the frame, so it appears to be a long way behind her. We had to shoot at the widest end of a standard zoom to include as much of the model as possible. This is not the most flattering focal length for portraits, as it tends to distort the features of the model, but it’s a good technique for landscapes when you want to include foreground interest.

Normal - 35mm

You don’t have to walk far, or change the focal length very much to alter the appearance and composition of your shots. Walking back a few yards and shooting with our standard zoom at the 35mm mark has produced a much more flattering portrait, while the background still looks to be far behind the model.

Short Telephoto 100mm

Moving back several metres and switching to a telephoto zoom changes the perspective of the shot completely. The trees in the background now look much closer to the model compared to the shots taken from close range with a shorter focal length. Note how the distant buildings have been cropped completely.

Long Telephoto zoom

With a longer focal lengths lens you need to be a long way from the model to keep the framing of the model the same as the other images. This more distant viewpoint has created the appearance of ‘compressed’ perspective that is commonly associated with long focal length lenses, where the trees in the background seem very close to the model.

Do telephotos really compress perspective?

It’s a common mistake to think that telephoto lenses compress perspective. The confusion is due to the face that most telephoto shots depict subjects a long way from the camera, and the change in perspective is due to the greater distance between you and the subject. So if you want to alter perspective, alter your viewpoint and choose a lens that fits the subject matter.