A long lens makes the background in a portrait look larger, closer and softer because you stand farther from the subject. To use it, choose a focal length such as 85mm to 200mm, step back, keep your subject away from the background and shoot at a wide aperture.
What Compression Really Is
Lens compression is often credited to the lens itself, but it is really about distance. A longer lens lets you stand farther away and still fill the frame with your subject. From farther away, the difference in distance between your subject and the background matters less, so the background appears bigger relative to the person. Nothing in the lens physically squeezes the scene; the change in your position does the work.
Choosing a Focal Length
| Focal length (full frame) | Typical use | Effect |
|---|---|---|
| 35mm to 50mm | Environmental portraits | More background context |
| 85mm to 135mm | Classic head and shoulders | Pleasant compression, easy blur |
| 150mm to 200mm | Outdoor portraits from afar | Strong compression, very soft backgrounds |
On a smaller sensor, the field of view is narrower, so the same lens frames the subject more tightly. Adjust your distance to match.
Step-by-Step Setup
- Pick a lens in the 85mm to 200mm range, or zoom to the long end of a telephoto zoom.
- Place your subject at least a few meters from the background. The more space between them, the softer the background becomes.
- Step back until the subject fills the frame the way you want.
- Use a wide aperture, such as f/2 to f/4, as a general guide for soft backgrounds.
- Use a shutter speed of roughly 1/250 or faster to avoid blur from handshake with a long lens.
- Focus on the nearest eye and check the result on the screen.
- Try small changes in your position and angle to see how the background shifts.
Choosing a Background
- Layers of trees or buildings look stacked and rich when compressed.
- City lights become large, soft circles behind your subject.
- Avoid busy lines that cross the subject’s head or shoulders.
- Look for backgrounds with an even tone or a color that supports the clothes.
Things to Watch
You will need more room, so a small indoor space may not work. A long lens also magnifies movement, so brace your arms or use a monopod. Communication gets harder at a distance, so agree on simple signals or use a quiet voice or a phone. Expect less of the surrounding scene to show, which suits portraits focused on the person.
FAQ
Does a longer lens change the way a face looks?
Standing farther away tends to give gentler proportions in the face, which is why longer lenses are popular for headshots.
Do I need a wide aperture to get compression?
No. Compression comes from distance, while aperture controls how blurred the background looks. They work well together.
The Short Version
Use a longer focal length, stand back, separate your subject from the background and open the aperture. The background looks bigger and smoother, and your subject stands out.
