Lens Compression and How it affects your Background

Did you know that a simple change to your focal length can dramatically change your photo? This post is all about Lens Compression and how it affects your Background.

I love putting out posts like this and is one of the reasons I started to document my journey into Shooting, Learning, and Sharing. I have done a lot of editing tutorials recently, but not many shooting ones, so, here we go!

As with most of my posts, I have a video to go along with this post. Don’t forget to check out all the videos over on my YouTube Channel, and thanks for checking out my website.

Video all about Lens Compression and how it affects your Background

If you don’t want to view the above, but want to read about it, then the rest of this post is for you


So I have always known Lens Compression is a factor, and it can have an impact on how it affects your Background but never really paid much attention to it.

Take a look at these two photos. One-shot at 24mm, the other at 400mm. Max, the subject, did not move. He stood in the same place for 5 minutes as I took the shot.

The remarkable thing about this photo was, that it is one of the few times he has actually done what I asked!! 🙂

Lens Compression and how it affects your Background

You can see the subject is virtually the same size in both but look at the difference in the background. I moved. I walked back and as I did, I was zooming in, with the intention of keeping him in the same place in the frame.

In the 400mm one, everything seems a lot closer. More Compressed. Now, I am not really going to go too much into the science of it all, mainly because I am probably not the best person to explain this.

Instead, I am going to show you how this may work in the real world.

The Len Compression Experiments

This was shot in the garden and I wanted to demonstrate with an outdoor photo so we can see just how different these two shots are.

The first one at 24mm, the background seems further away. Take this out to 400mm, and now look at the background.

I promise you he didn’t move.

Here are a few more.

Max did not move from the first photo to the last.

I did though. I moved back, and zoomed in so he was the same size in the frame in all of them. Just look at the difference in the background!

Let’s Look at things a bit closer.

Equipment, Focal Lengths and settings

If it helps, here is a bit of information about the equipment used here.

All the photos were shot using the same Aperture, f11. We all know how Aperture affects Depth of Field so I wanted to make sure there were no changes in the aperture. When I changeed from one lens to the other, I did have to change the shutter speed and ISO, but the Aperture remained constant.

In order to explain Lens Compression and how it affects your Background, I did have to use a couple of lenses.

For the photos up to 70mm, I used the 24-70 lens, and for the others, I used my 100-400 lens.

Lens Compression and how it affects your Background – 24mm to 400mm

Shot at 24mm

Let’s look at the first photo, the 24mm


Lots in the background.

The Swing on the left is visible, and all the trampoline on the right is well in view. You event get a glimpse of our stunning fence panels!

Shot at 50mm


I take a few steps back. Max stays still, so I zoom in a little too 50mm.

The swing is now gone. The trampoline is now touching, the edge of the frame. The Lens Compression is already starting to show in the background.

Shot at 100mm


There is now quite a significant difference. The shed on the left has totally disappeared.

On the right, the trampoline has started to be cropped out too.

Shot at 215mm


We are now at over 200mm, and the battered old playhouse on the left is starting to go

In addition, the Lens Compression has meant the trampoline is well and truly being brought closer to Max.

Shot at 400mm


Now zoomed right into 400mm, it almost looks like Max is standing right in front of the trampoline, when we know from the first photo this isn’t the case.

The Indoor Test

I also took the Lens Compression test indoors, to see how it affects the back ground on smaller object. A scene that was less expansive, with more close up detail.

This was a simple set on a table, but it proves that Lens Compression affects your background in either setting.

As you can see, the lens is a similar size in each, but look at the difference in the items in the background. This again, is just from moving back and zooming in.

Lens Compression and how it affects your Background – Summary

It is worth taking a bit of time when shooting that next shot, just to see what a difference a simple Focal Length change, or lens change could make. Perhaps you are shooting a subject, and you have them in a location where just a small movement will make a huge difference.

Move back and to the left, zoom in, go back a long way and REALLY zoom in. You could get a multitude of different photos. All with the subject staying in the same place.

Anyway, that is enough for today, I hope you find it useful. Don’t forget to check out my YouTube channel, or sign up for the newsletter to get tips, tricks and tutorials direct to your inbox!

See you next time.