Understanding lens perspective is critical to advanced photographic studies and skills. It is the skill of learning how the lens sees. For some, the concept of photography lens perspective is simple. The wider the lens the wider the view, the longer the lens the narrower the view. Yet, lens perspective is much more interesting and important to photographers.
Lens perspective impacts what is captured and “seen” on the film, the amount of foreground and background included, and the working distance between the photographer and the subject.
Lens Perspective – What the Lens See
The wider the lens, the wider the perspective. The longer the lens, the narrower the perspective. This appears to be a pretty basic statement. The more the lens sees, the more goes onto the film. The less the lens sees, the less goes onto the film.
Wide angle lenses see the whole picture. Wide angle lenses range from 50mm to 20mm or smaller, with lenses beyond 20mm, like 17mm, 14mm, and 8mm, as extreme wide angle or fish-eye lens. Wide angle lenses see a wider perspective, showing everything in the viewfinder. This means the photographer must take greater care with what goes into the viewfinder before they press the shutter.
Remember, you are telling a story with your photograph and every character in your story matters. With a wide angle lens, your angle of view includes everything in your landscape, including the garbage can, the signs, telephone poles, mountains, sky, and parked cars. If you want all those in your photograph, then fine, but if you don’t, you need to position yourself so only the subjects that help you tell your photographic story are in the picture.
In contrast, the longer the lens, the narrower the view. Switch to a longer lens and suddenly the garbage cans, signs, poles, sky, and parked cars don’t matter. You’ve narrowed the view to your subject, leaving out all the extraneous detail. In other words, you’ve zoomed in on the subject and now what was just a part of the overall scene is the focal point of the photograph.
Longer lenses are anything longer than 50mm such as 100mm, 200mm, 400mm, etc.
A 50mm lens, however, is considered a “normal” lens, not just because it used to “normally” come on any camera body purchase, but because it is closes to what the eye sees “normally”, which is about 55mm. If you want to photography, literally, what you see, then stick as close to a 50mm lens (35-70mm range) to capture your eye view.
Lens Perspective: Magnification
There are reasons other than magnification to choose a particular lens. One of the most important of these reasons is the change of perspective afforded by using lenses of different focal lengths.
A wide angle lens sees a wide angle of view. The first thing people think of is that a wide angle lens will let them include more of a scene in the image, and this is true. What they don’t consider, however, is what the short focal length will do to the appearance of the subject.
If you were to make a head and shoulders portrait of your best friend using a 20mm lens, you would have to stand a distance of about a foot (30 cm) away from him. At this distance, his nose would be much closer to the lens than his ears, and so the nose would be much bigger proportionally than the ears in the photograph. This is generally not a flattering effect, and so we don’t use wide angle lenses to photograph closeups of people.
The same effect happens when we photograph flowers closeup with a wide angle lens. The parts of the flower that are closer to the lens appear proportionally bigger in the resulting photograph than the other parts of the flower, or than the other flowers in the picture. A wide angle lens will cause objects closer to the lens to appear proportionally larger in the photograph than the other objects in the picture. This is useful for separating an object from surrounding objects, making the objects appear farther apart. Wide angle lenses seem to expand space.
Telephoto lenses magnify objects. More than this, however, they affect the appearance of objects in a photograph. Using a 100mm lens to make the same head and shoulders portrait of your friend as you made with the 20mm lens, you would have to stand back about 10 feet (3 or 4 meters). At this distance, the nose and ears are all approximately the same distance from the lens, so there is no apparent distortion of perspective. The person will appear as we expect him to appear, because we’re used to seeing people from across a room. We don’t usually see people from extremely close up, and so the view from the 20mm lens seems strange to us. If there are other people in the picture, they will also appear normal.
If we move to a very long telephoto lens, like a 500mm or 600mm lens, we would have to move backward 25 or 30 feet (10 meters) to photograph our friend. The magnification power of this lens is high. A person standing a few feet behind him would appear to be nearly at his side, because the difference of a few feet compared to 30 is small. The large telephoto lens has a perspective that seems to compress space, magnifying distant objects equally.
We can use this difference in perspective between lenses to our advantage. Any time we want to separate a foreground element from a background, we can use a wide angle lens. Any time we want two objects to appear close together, we can use a long telephoto.
Lens Perspective: Control of Background
The background is an important part of any photograph. A wide angle lens has a wide angle of view. That means that it will include a large amount of background behind the subject. Everything, from the mountains to the trees to the parking lot with all the cars can appear in the background of a wide angle photograph. A telephoto lens, however, has a narrow angle of view. That means that it sees a smaller amount of background behind a subject. By using a telephoto lens, we can choose the part of the background that we want behind our subject, excluding everything else. For this very reason, a 200mm lens is a much more useful lens for closeup work than the more common 50mm lens. A 500mm lens is much more useful for wildlife photography than a 200mm lens for a number of reasons, but one of the most overlooked is its ability to control the background. Control of the background is essential to good photography.
Photography turns a three dimensional world into a flat one dimensional image. Depending upon the lens perspective, the combination of optics and focal lengths you are using, the aperture, and the distance to your subject and to the background, things in the distance can suddenly become very close when flattened into a photograph. This is usually the cause of the tree growing out of the head, when the tree is meters away in the background but the photograph is compressed so the branches look like they are growing right out of the skull.
Lens perspective is the view of the scene, including the background, that is captured onto the film through the lens. A wide angle lens sees a wider angle of view, therefore it captures a wider perspective. A long telephoto lens sees a very narrow view, therefore it captures a narrow perspective. In these three photographs of a marmot in the Olympic National Park, we kept our subject, the cooperative marmot, basically the same size in the frame. We’ve moved either further or closer to our subject and changed the focal length of the lens to change our background, since different focal lengths change the background perspective behind the subject. Across the valley, more than a mile away, rose a mountain with the last of the winter’s patches of snow on its steep sides. A 200mm lens, the shortest lens used in this series of photos, sees a lot of the background. You can see the snow on the far mountain, though it’s not clear if the white blobs are snow, clouds, or cartoon thoughts coming from the marmot.
Brent changed to a 300mm lens and moved farther back from the marmot to keep him about the same size in the frame. The 300mm lens sees a bit narrower perspective than the 200mm, so the white snow is just a blurry bit in the corner. Moving even further back, Brent changed to a 500mm lens with its very narrow perspective and the white snow packs are gone and the marmot is isolated against a green background.
Using this technique and understanding how the lens “sees” and change the background perspective, you can isolate your subject against a more interesting or appropriate background by simply changing lenses. This opens up your options on background composition.
In this example, we set up a dried teasal in the backyard.
A wider angle lens like a 55mm requires a close working distance to photograph the subject and, as it sees a wider perspective, captures a lot of background. We see the out-of-focus parking lot and buildings in behind as well as the green grass.
By moving backward from the subject, keeping it the same size in our viewfinder and not changing the exposure, we increase the magnification by using a longer lens such as a 200mm. Longer lenses narrow their view so you see a narrower perspective of the background.
Now, only the green grass in the background is visible, isolating the subject against a neutral and undistracting background. Using a longer lens can help you to choose your background.
Either lens could have produced this image. The difference is in the working distance.
A 55mm lens requires a much closer working distance to get the exact same image.
A 200mm lens requires a greater working distance to reproduce the same image.
For most subjects in nature, the distance your camera is from the subject won’t influence the subject. But photographing insects, butterflies and such, can be difficult because they are exceptionally attentive to your location and will respond accordingly – often by escaping the situation. Being able to get close and still maintain some distance becomes critical then. Add to this the challenge of low light, and the closer you are to the subject, the greater the chance of casting a shadow.
By using longer lenses, your distance from the subject and the camera increases. This is called the working distance. Working with live creatures, this distance is critical. Either way, it’s nice to have some room between the camera lens and the subject. Here are some examples of working distance based on the closest focusing distances of typical lenses.
|Closest Focusing Distance||138″||84″||42″||18″|
Using a longer lens, you can maintain the subject at the same size but increase the “working distance” between you and the subject. For body heat sensitive nature subjects like spiders and spider webs, maintaining distance is critical. The same stradegy applies when photographing grizzly bears and other large and potentially dangerous creatures. The greater the working distance the safer you may be.
The greater your magnification is ehanced through the use of extension tubes and teleconveters, the more your working distance is cut. You must move closer to your subject to find the focus point.
Play around with the lens equipment you have and see how your lens sees depending upon how far you are from your subject and how big your subject is in your frame across the range of lenses. Make notes and work with the various lenses to learn how they see, so when you are out in the field, you will know automatically which lens to pick for which subject matter and working distance.
For more information on controlling the background of your subject with lens perspective, see our articles on Background Magic, Specific Crimes of Ignoring the Background in Photography, and Behind the Scenes of Background Magic.