What is Lens Compression and How to Use It In Your Photos

Ever heard someone tell you that a telephoto lens “flattens” an object or compresses the background? What does this actually mean? Two factors affect the perceived distance between your subject (or subject) and the rest of a scene: the position you take the photo from relative to your subject, and the focal length of your lens. This article will discuss perspective distortion and how it can be used to create exciting photos.

What Lens Compression isn’t!

I have often heard photographers say that images taken with a telephoto lens will appear to have a shorter subject-to-background distance than those taken with a wide angle lens. It isn’t true. You can take two photos of the exact same location, one with both a wide angle lens as well as one with a zoom lens. They will appear the same distance from the front and back, because the perspective hasn’t changed. This is shown by cropping an image with a wide-angle lens to get the same field as a zoom lens. Yes, the crop quality will be terrible, but that’s beside the point. The point is that the crop will be identical to the telephoto shot.

These are two images. The first image was taken at 24 mm focal length, and the second at 70 mm focal length. The shots were taken exactly from the same spot, using a tripod. I concentrated on the bridge in the middle of the images.

Biloxi Bridge 24
Biloxi Bridge 70

Now, I will crop the wide shot to make the composition the same as the one with the telephoto lens. Comparing the photos, I had to increase the crop by 285%. This is not something I recommend. This crop is identical to the 70 mm shot. The bridge is not distorted, and the railing at the fishing pier (on right) is still in the same place. This means that there was no distortion of the focal length and no “compression”.

Biloxi Bridge Crop

Their depth of field is the only difference. The sharpness of the foreground in the 70 mm photo is less than that at 70 mm. The depth of field is not just a property of aperture but also of focal length and camera-to-subject distance. But that’s another topic!

In the above example, the distance between the camera and the subject didn’t change. The image’s proportions did not change as a result. The effect of a telephoto lens is identical to cropping if your feet are still stationary when you take a photo. However, it does not lose detail or sharpness like a crop.

What is Lens Compression?

What is lens compression? Lens compression occurs when you take pictures with a long-telephoto lens. However, it is not due to the focal length of the lens. Long lenses cause us to be closer to our subjects. The combination of a long lens and camera distance to the subject gives the viewer an illusion that distant objects are larger than their actual size. It gives the impression that the background is pulling closer to the subject. Wide angle lenses can have the opposite effect. Wide lenses tend to be closer to the subjects than telephoto lenses. This relative closeness makes objects nearer to us appear larger than those further away. The background elements will appear further away because they are smaller.

These are just two examples. This is the first shot. I used a long lens. You can see how close the freighter is to the birds. They were only about a kilometre apart in reality.

Pelicans

This photo of a goat was taken with a wide angle lens. You can see how big the goat’s head is relative to his body.

Goat Kiss

It is important to note that I did not use different lenses. The fact that the distance between my subject and camera was vastly different in each of these pictures is what is most important. The distance between my camera and the subject (birds or freighter) was approximately 100 metres for the picture of birds and bird. My camera was only inches from the goat’s nose in the goat photo.

These two examples are not sufficient to explain lens compression, as they are from two different subjects. Let’s look at some photographs to understand why compression occurs. These photos were taken so that my patient and cooperative daughter, the subject, appears nearly the same in each one. To achieve this effect, I had to move my camera further away from my daughter each time I increased her focal length. This is something that I will do again. To keep her in the frame, I had to adjust her distance from the camera. Pay attention to the background. Please note that I am not a portrait photographer so please don’t make harsh comments about lighting or poses.

The 24mm setting is used for the first image. The background is large and gives the viewer a sense that they are in a place. The flag is visible, as well as the distance between the flower planters. My daughter’s nose looks a little too big because she was so close to me.

Lisa 24

The focal length for this next shot was 70mm. The flag looks larger. Notice also what’s happening to the trees in background. The planters seem to be closer as well.

Lisa 70

105mm The flag is no longer visible. The cherry blossom trees are more prominent.

My focal length now measures 200mm. The background is becoming even closer. It’s difficult to feel distances.

Lisa 105

This last image was taken at 300mm. These planters were only 10m apart in real life, but they look so close now.

Lisa 200

The distance between the subject and the camera is what causes compression. You will need to step back when using longer focal lengths, which have a smaller field of view, to ensure that your subject is the same size as the rest of the frame. Wide angle lenses have a wider field of vision. You need to be very close to your subject to keep it the same size in wide angle images. The distance between my daughter and the background in the above shots didn’t change. It was the distance between the camera and her that changed as I adjusted focal lengths.

Lisa 300

This is how it works: It will appear larger if it is near you. The object’s size will be halved if you double the distance between yourself and it. The object will be one-tenth its size if you increase the distance by ten. The distance between my daughter’s camera and the background is shorter in the wide angle cases than between my daughter and it. Lisa is therefore larger than the trees, as objects seem smaller with distance.

Because they are so far apart from each other in the telephoto cases Lisa and the background look closer together. As I increase the distance between Lisa and the background, the difference between them is less.

Subject Background Distance Ratio

Lens Compression and Composition

Lens compression can be used to your advantage if you realize that the distance between your subject and the camera causes distortion. If you’re trying to capture a portrait and are faced with distracting elements in your background, you can use a long lens and stand back from your subject. You can focus on your subject and eliminate the clutter by stepping back.

Horse and Rider
Hummer

A wide angle lens can help you show the vastness and beauty of a landscape. This will make distant elements seem even larger.

Glacier Park
Marine Iguanas

Conclusion

To summarize, the background will appear farther away than the subject the closer the camera is to it. This will magnify the distance between background and subject. The background and foreground will appear closer if you move the camera further away from your subject. This will create intimacy between your subject, and distant backgrounds.

Think about the distance between your subject and your camera when you’re creating photos. Instead of zooming in and out with your lens, move your feet! You can get closer to your subject using a wide lens, or further away with a Telephoto. Try this technique to see how it affects the dynamic of your photos. Have fun!