Depth of field

Definition

Depth of field, often shortened to DOF, is the distance between the nearest and farthest objects in a photograph that appear acceptably sharp. A shallow depth of field means only a small part of the image is in focus, often used to isolate a subject from the background. A deep depth of field means that most or all of the scene is sharp from foreground to background.

Depth of field is controlled by a combination of aperture size, focal length, distance to the subject, and sensor size. It is a key creative tool for photographers and videographers, as it influences how the viewer’s attention is guided within the frame.

Advanced

At an advanced level, depth of field is calculated using formulas that consider circle of confusion, focal length, and aperture. Hyperfocal distance is another important concept, referring to the closest focusing distance that keeps objects at infinity acceptably sharp.

Photographers use depth of field creatively to manage storytelling. Wide apertures like f/1.8 create shallow depth for portraits, while narrow apertures like f/16 maximise depth for landscapes. In cinematography, depth of field also influences visual style and emotional tone, with shallow focus often used for dramatic emphasis.

Why it matters

• Guides viewer attention to the most important subject.
• Creates artistic effects such as background blur (bokeh).
• Helps control storytelling in photography and film.
• Essential for balancing technical and creative needs in exposure.

Use cases

• Portraits with shallow depth of field to separate the subject from the background.
• Landscapes with deep depth of field for sharpness across the frame.
• Product photography where selective focus highlights details.
• Cinematic shots where depth guides emotional focus.

Metrics

• Aperture value (f-stop) controlling depth of field range.
• Focal length impact on compression and background blur.
• Subject distance relative to lens and background.
• Hyperfocal distance calculations for maximum sharpness.

Issues

• Too shallow a depth can cause important details to fall out of focus.
• Excessively deep depth may flatten the image or distract viewers.
• An incorrect focus point reduces image quality even with proper settings.
• Overuse of blurred backgrounds may limit creative variety.

Example

A portrait photographer uses f/2.0 on an 85mm lens to create a shallow depth of field. The subject’s face is sharp while the background is softly blurred, producing strong subject isolation. In contrast, a landscape photographer sets f/11 on a wide-angle lens to capture mountains, forests, and sky all in sharp focus.