Depth of field is the range of distance in your image that appears acceptably sharp. A shallow depth of field means a thin slice of the scene is in focus with the rest blurred. A deep depth of field means everything from near to far is sharp.

Understanding what controls it gives you creative power over every photograph you take.

The Three Factors That Control Depth of Field

1. Aperture

This is the most well-known factor. A wide aperture (small f-number like f/1.8) produces shallow depth of field. A narrow aperture (large f-number like f/11) produces deep depth of field.

  • f/1.4 – f/2.8: Very shallow. Only a thin plane is in focus. Great for isolating a subject from the background.
  • f/4 – f/5.6: Moderate. The subject is sharp with a gently blurred background. A versatile range for portraits.
  • f/8 – f/11: Deep. Most of the scene is sharp. Ideal for landscapes and group photos.
  • f/16 – f/22: Very deep. Nearly everything is in focus. Note: at these values, diffraction can actually reduce overall sharpness.

2. Distance to Subject

The closer you are to your subject, the shallower the depth of field — regardless of your aperture setting. This is why macro photography has an extremely thin plane of focus even at f/8, and why landscape photos taken from a hilltop have deep focus even at wider apertures.

This also means you can increase background blur simply by moving closer to your subject (and zooming out to maintain the same framing).

3. Focal Length

Longer focal lengths produce shallower depth of field at the same framing distance. A 200mm lens produces much more background blur than a 24mm lens when the subject fills the same portion of the frame.

This is why portrait photographers love 85mm and 135mm lenses — they naturally separate the subject from the background.

How to Visualize It

Imagine depth of field as a flat plane perpendicular to your camera, extending forward and backward from your focus point. Everything within that plane is sharp. Everything in front of and behind it gets progressively blurrier.

Key detail: The plane extends further behind your focus point than in front of it. Roughly one-third of the depth of field is in front of the focus point and two-thirds is behind it. This means if you’re photographing a group, focus on the person in the front third of the group, not the center.

Creative Uses

Shallow depth of field for isolation: Portraits, product photography, food photography. The blurred background (called “bokeh”) eliminates distractions and draws attention to the subject.

Deep depth of field for context: Landscape photography, architecture, street photography. Keeping everything sharp tells a complete visual story where the environment is as important as the subject.

Selective focus for storytelling: Focusing on one element while others blur guides the viewer’s interpretation. A sharp child in a blurry crowd tells a different story than a sharp crowd with a blurry child.

Common Misconceptions

“I need an expensive fast lens for shallow depth of field.” Not necessarily. Getting physically closer to your subject with a kit lens produces noticeable background blur. A 50mm kit lens at f/5.6 with the subject close creates decent separation.

“Wider aperture is always better for portraits.” Shooting a portrait at f/1.4 means the tip of the nose might be sharp while the eyes are soft. Many professional portrait photographers shoot at f/2.8 to f/4 for reliable sharpness across the face.

“Landscape photos should always be at f/16 or smaller.” Most lenses are sharpest at f/8 to f/11. Going smaller than f/11 introduces diffraction that softens the image. For landscapes, f/8 with careful focus placement often produces sharper results than f/16.

How to Practice

Set your camera to aperture priority mode and photograph the same scene at f/2.8, f/5.6, f/8, and f/16. Compare the results on your computer. Seeing the progression from shallow to deep focus with the same composition is the fastest way to internalize how aperture affects your images.