Lens Compression Calculator — Perspective Compression

Lens compression (more accurately, perspective compression) makes the background appear larger and closer to the subject. It is caused by camera-to-subject distance, not focal length. When you use a telephoto lens, you stand further away — this distance creates the compression effect. Cropping a wide-angle shot from the same position gives identical compression.

No — distance does. Focal length only determines magnification (how much of the scene you capture). Two photos taken from the same distance with different focal lengths show identical perspective when the wider one is cropped. The compression changes only when you move the camera.

Use compression to make backgrounds appear closer (telephoto from far away) — great for bringing mountains behind a subject. Use wide-angle close up to exaggerate distance and depth. Portrait photographers use moderate compression (85-135mm on FF) for flattering facial proportions.

When you photograph a face up close with a wide-angle lens, the nose is much closer to the camera than the ears. This distance difference is exaggerated, making the nose appear larger. At telephoto distances, the nose-to-ear distance is tiny relative to camera-to-subject distance, so proportions look natural.