Bokeh

In <a href="/facts/Photography/ezLPT43M">photography</a>, bokeh is the aesthetic quality of the blur produced in <a href="/facts/Defocus_aberration/AuE5r5Wv">out-of-focus</a> parts of an image, whether foreground or background or both. It is created by using a wide aperture lens.
Some photographers incorrectly restrict use of the term bokeh to the appearance of bright spots in the out-of-focus area caused by <a href="/facts/Circle_of_confusion/jyuuTIUa">circles of confusion</a>. Bokeh has also been defined as "the way the <a href="/facts/Lens/ejlH6n5c">lens</a> renders out-of-focus points of light". Differences in <a href="/facts/Optical_aberration/YIqd9cA8">lens aberrations</a> and <a href="/facts/Aperture/8PV11GQm">aperture</a> shape cause very different bokeh effects. Some lens designs blur the image in a way that is pleasing to the eye, while others produce distracting or unpleasant blurring ("good" and "bad" bokeh, respectively). Photographers may deliberately use a <a href="/facts/Shallow_focus/en2HQsGs">shallow focus</a> technique to create images with prominent out-of-focus regions, accentuating their lens's bokeh.
Bokeh is often most visible around small background <a href="/facts/Point_source/AHmNlt03">highlights</a>, such as <a href="/facts/Specular_reflection/dwVIqLVb">specular reflections</a> and <a href="/facts/List_of_light_sources/FRTheSWG">light sources</a>, which is why it is often associated with such areas. However, bokeh is not limited to highlights; blur occurs in all regions of an image which are outside the <a href="/facts/Depth_of_field/xWo3J8b0">depth of field</a>.
The opposite of bokeh—an image in which multiple distances are visible and all are in focus—is <a href="/facts/Deep_focus/YTQEQ2It">deep focus</a>.

Bokeh open-in-new

Bokeh