Shallow focus is a photographic

Photography

Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...

 and cinematographic

Cinematography

Cinematography is the making of lighting and camera choices when recording photographic images for cinema. It is closely related to the art of still photography...

 technique incorporating a small depth of field

Depth of field

In optics, particularly as it relates to film and photography, depth of field is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image...

. In shallow focus one plane of the image is in focus while the rest is out of focus. Shallow focus is typically used to emphasize one part of the image over another. Photographers sometimes refer to the aesthetic character of the area that is out of focus as bokeh

Bokeh

In photography, bokeh is the blur, or the aesthetic quality of the blur, in out-of-focus areas of an image, or "the way the lens renders out-of-focus points of light."...

.

The opposite of shallow focus is deep focus

Deep focus

Deep focus is a photographic and cinematographic technique using a large depth of field. Depth of field is the front-to-back range of focus in an image — that is, how much of it appears sharp and clear. Consequently, in deep focus the foreground, middle-ground and background are all in focus...

, in which the entire image is in focus.

How to

The effect can be obtained by a wider aperture

Aperture

In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane. The aperture determines how collimated the admitted rays are,...

, a close viewpoint, or using a longer focal length

Focal length

The focal length of an optical system is a measure of how strongly the system converges or diverges light. For an optical system in air, it is the distance over which initially collimated rays are brought to a focus...

 lens from a greater distance. A tilt lens

Tilt-shift photography

"Tilt-shift photography" refers to the use of camera movements on small- and medium-format cameras, and sometimes specifically refers to the use of tilt for selective focus, often for simulating a miniature scene...

 can be used, in the opposite way to that used to increase depth of focus.
There are even adapters

Depth-of-field adapter

A depth-of-field adapter is used to achieve shallow depth of field on a video camera whose fixed lens or interchangeable lens selection is limited or economically prohibitive at providing such effect...

 that allow lenses from 35mm cine cameras to be used on smaller film and digital formats.

Examples

In the film, The Rules of the Game

The Rules of the Game

The Rules of the Game is a 1939 French film directed by Jean Renoir about upper-class French society just before the start of World War II...

(1939), a couple flirts in the foreground while the woman's husband enters in the background. Director Jean Renoir

Jean Renoir

Jean Renoir was a French film director, screenwriter, actor, producer and author. As a film director and actor, he made more than forty films from the silent era to the end of the 1960s...

chooses to keep the husband out-of-focus so that his presence is hinted, but not emphasized.

External links

• Background blur, discussion and calculator.