How to use perspective to make your photos more interesting

Add depth,distance, and realism -- or fake it -- with these techniques

How to use perspective to make your photos more interestingWe've talked about depth of field and its relation to both aperture and shutter speed. This week, we're going to take an in-depth look at something that is intricately linked to depth of field:perspective

kmg 300 perspective hallway bertkauffmanJust the facts, please
Put very simply, perspective refers to the visual cues our mind uses to interpret a two-dimensional photograph as a three-dimensional scene. Perspective -- specifically linear perspective -- is the way in which objects appear based on their position relative to the viewer. In other words, if you place a basketball close to you and place another one further away, the second ball will appear smaller. Your brain knows the approximate size of a basketball and interprets the fact that one is smaller than the other to mean that the smaller one is more distant.

Seems pretty obvious, right? Perspective is largely instinctive. Humans are pretty good at interpreting perspective to extrapolate information from a 2D image. But perspective can also be used to trick the human eye into seeing things that aren't there or interpreting them in wildly erroneous ways. Many optical illusions are based on tricky use of perspective.

kmg 300 perspective forced flickr iurigueraForcing the perspective
Forced perspective is a technique that uses optical illusion to apparently distort the size of objects. It's used quite a bit in filmmaking; for example, a much smaller-than-life model of something like a castle is filmed much closer than the real thing would be, thus giving the illusion of a real castle farther away. Another example would be using smaller props during a scene with someone who's supposed to be a giant or larger ones for a scene with dwarfs. 

In photography, forced perspective can be used for comedic effect, in those iconic photographs of people who appear to be holding up the Leaning Tower of Pisa, squishing the Eiffel Tower, or poking the Statue of Liberty. To achieve this effect, you have to use a very wide depth of field (that is, a small aperture such as f/18, f/22 or higher) so that both the closer subject and the one farther away are in focus. 

Head toward the vanishing point
You've probably noticed that parallel lines that head into the distance, such as train tracks or the edges of a road, seem to grow closer together the farther away they get. This is a phenomenon known as the vanishing point, and it refers to a specific point on the horizon where parallel lines appear to eventually converge. Architectural drawings make use of this phenomena to show how a building looks in three dimensions.
kmg 630 perspective railroad flickr sonofgroucho
One of the best ways to use perspective and the idea of the vanishing point in photography is for photos with a great deal of symmetry. Look for a place with long, straight parallel lines such as a road, train tracks, or a tunnel. Usually, photographers take these picture from the exact center of the lines, so that the lines start on either side and continue ahead until they appear to meet at the horizon. This gives the viewer a sense of size and scope in the scene, and it makes for a lovely abstract photo as well.

kmg 300 perspective tall building flickr michaeldaddinoKeeping things straight
Sometimes being able to clearly see the lines of objects in a scene converging toward the vanishing point is not desirable. If you're trying to take a photo of a tall building that's close by, for example, you'll probably have to tilt the camera upwards, and you'll notice that the top of the building appears to "shrink" toward the center. While this effect is sometimes useful for exaggerating how tall a building appears, sometimes you would prefer not to see such distortion. 

One simple way to combat this to some extent is to use a lens with a long focal length. A wide-angle lens with a short focal length distorts the objects at the edges of the field of vision (and would make the distortion of the building even worse), while a long telephoto lens appears to compress the distance between objects, thus making the distortion slightly less acute.

kmg 300 perspective tilt shift flickr thalesA better way to deal with the problem is a tilt-shift lens. These lenses actually tilt the lens in relation to the camera to allow for a straighter view of the subject. Thus, you can get a tall building in the frame without as much distortion toward the higher elevations.

Tilt-shift lenses can also be used to create optical illusions. One popular method takes a wide scene such as a cityscape and uses a tilt-shift lens to exaggerate the blur before and behind the focal plane. This makes it appear as though you're looking at a miniature landscape like a train set model.

Keeping it real -- or not
Perspective is one of the tools in a photographer's vast artistic arsenal. It's one of the things that you should keep in the back of your mind as you're shooting. How does perspective affect the shot's composition, and is it doing so in a way that you like? Use these techniques to your advantage to help you control perspective, rather than letting it control you.

[Writing Credit: Katherine Gray. Image credits: K. Gray, Bert KaufmannIuri GuerraMiusam CKThales]


Thanks to our friends over at Tecca for submitting this helpful how to.  Find more How-to tech articles & Gadget news at Tecca.com.  And, as always, if you have any sweet perspective shots (like this one from Steve's fan, Emil Johnson), post 'em on Steve's Facebook Wall, or hit up the Steve's Forums to talk about this article, ask questions, or anything photography related.