bakgrundsoskärpan

Bakgrundsoskärpa, often translated as "background blur" or "bokeh," is a photographic and cinematographic effect that describes the way out-of-focus areas of an image appear. It is not about the subject being out of focus, but rather the intentional rendering of the background into a soft, pleasing blur. This effect is achieved by using a shallow depth of field, which is controlled by aperture, focal length, and the distance between the camera and the subject.

The aesthetic quality of bakgrundsoskärpa is highly subjective, but it is generally characterized by smooth transitions and often, attractive shapes formed by light sources in the background. These light sources, when out of focus, can appear as circular or polygonal blobs, which are a hallmark of good bokeh. The specific quality of the blur depends on the lens's design, particularly the shape and number of aperture blades. Lenses with more, rounded aperture blades tend to produce smoother, more circular out-of-focus highlights.

Photographers use bakgrundsoskärpa to isolate their subject from the background, drawing the viewer's eye and minimizing distractions. This technique is particularly common in portrait photography, where the aim is to emphasize the person being photographed. In videography, it is used to create a cinematic look and to guide the audience's attention. While the term itself is Swedish, the concept and its application are universal in visual arts.