What Is Bokeh?
Bokeh (pronounced BOH-keh) describes how a lens renders the parts of an image that fall outside the plane of focus. It is not simply “blur” — two lenses can produce equally blurry backgrounds that look very different. One might create smooth, creamy circles of light, while another produces harsh, busy patterns. The first has good bokeh; the second does not.
The term comes from the Japanese word “boke,” meaning blur or haze. It was adopted by the photography community to describe a quality that photographers had long noticed but lacked precise vocabulary for.
What Creates Bokeh?
Bokeh is produced whenever your depth of field is shallow enough that parts of the scene fall out of focus. Three factors control this:
Aperture is the primary driver. Wider apertures (f/1.4, f/1.8, f/2.8) produce shallower depth of field and more prominent bokeh. The shape of the aperture blades also matters — lenses with more blades (typically 7-11) and rounded blade edges produce rounder, smoother out-of-focus highlights.
Focal length amplifies the effect. A 135mm lens at f/2 produces significantly more background blur than a 35mm lens at the same aperture, even from a distance that frames the subject similarly.
Subject-to-background distance plays a crucial role. The farther your background is from your subject, the more blurred it becomes. A portrait taken with the subject three feet from a wall shows mild bokeh; the same portrait with the background thirty feet away shows dramatic bokeh.
Good Bokeh vs. Bad Bokeh
Photographers describe bokeh as “smooth,” “creamy,” or “buttery” when out-of-focus areas transition gradually and highlights render as soft, even circles. This is considered good bokeh.
Bad bokeh has harsh edges on out-of-focus highlights, busy or “nervous” patterns in the blur, and distracting onion-ring shapes within the circles. These artifacts draw attention to the background rather than letting it recede.
Lens design determines bokeh character. Prime lenses with wide maximum apertures — such as an 85mm f/1.4 or 50mm f/1.8 — are specifically valued for their bokeh quality. Some lenses are engineered with special elements to smooth out-of-focus rendering.
Practical Examples
Portrait photography: Shoot at f/1.8 to f/2.8 with a short telephoto lens (85mm to 135mm). Place your subject well away from the background. Street lights, foliage, and city textures dissolve into beautiful, non-competing circles and washes of color.
Macro photography: Even moderate apertures produce dramatic bokeh at close focusing distances. Flowers photographed at f/4 on a macro lens show stunning background blur because the depth of field at close range is measured in millimeters.
Night photography: Point lights — string lights, distant traffic, city illumination — become glowing orbs in bokeh. The shape and quality of these orbs directly reflects the characteristics of your lens.
Creative Uses
Bokeh is not just a byproduct — it is a compositional tool. Smooth, warm-toned bokeh can establish mood. Colorful bokeh from holiday lights creates festive atmosphere. Even the bokeh itself can become the subject, with abstract compositions built entirely from out-of-focus light sources.
ShutterCoach evaluates background rendering in your images, identifying when your aperture and lens choices create effective subject isolation and when adjustments might produce more pleasing out-of-focus areas.