An After Study of Lens Compression
This may sound a little strange, but when I’m out shooting with my family, I’m a shoot first, think about it later kind of photographer. What I mean by that is, I don’t always have the time to take into account my composition and all the other technical aspects of photography when I’m setting up my shots, due to bored and tired children (and wife). This is true with an image that I posted a few days ago. We were in the Cades Cove area of the Smoky Mountains a few weeks ago and I noticed a single dogwood that seemed to pop out from the rest of the background. So I took a shot of it using my zoom lens with a focal length of 175mm.
When I got home and started processing my shots from that trip, I noticed how this one particular shot seemed to be a little “flat”, in that everything seemed to have been smooshed together. But, seeing the one dogwood against the “flat” full background of green trees, really made the shot stand out. It was then that I realized that the lens had created a compression effect.
What is Lens Compression?
In the past I had heard of “lens compression” but it was never really explained to me.
Lens Compression is what happens when you take a picture with a longer lens. It is the perceived phenomenon that a lens with a longer focal length appears to decrease the depth perspective. The longer lens compresses the foreground and the background making things appear closer than they really are.
Experiment Time
Today I asked my kids to help me out with a little demonstration. I asked them to stand about 20 feet apart with my daughter in the foreground and my son in the background. Using my zoom lens I took two images. One at 200mm and the other at 55mm. Because of the lens compression, the first image at 200mm makes the children look like they are very close together. The second image at 55mm shows them spread apart. My son looks further away and smaller in the second shot compared to the first. For all there shots of my children in this post, they are standing at the same distance apart. I had to take each image at a different distance from my daughter.
200mm | 55mm |
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Added Bonus – 12mm
To add to this demo, I decided to use my wide-angle lens to show how they would look with the same distance apart, but at a focal length of 12mm. At this point my daughter was ready to move on and go play, but you can clearly see that the wide-angle lens really highlights the foreground and creates further distance between the foreground and the background.