
The term “bokeh” was made popular in the late 1990s by Mike Johnston, the editor of Photo Techniques magazine, who produced a series of articles on the subject for his publication. Based on the Japanese term “boke-aji,” it was used to describe the quality of the blurry or hazy portions of a photograph. The term quickly weaseled its way into the lexicon of desirable lens attributes. The funny thing is, many photographers still aren’t quite clear as to what bokeh really is.
Resolution, contrast, color quality, and distortion are lens qualities that are easy to define and qualify. A lens is sharp, or it isn’t sharp. The colors are neutral, or they have a cast. The lens distorts, or it doesn’t distort. But bokeh? That’s a hard term to nail down.
Let’s start by defining bokeh, which for the record, is not another way of describing narrow depth of field or selective focus. Narrow depth of field and selective focus are components of bokeh, but neither truly defines bokeh.
Bokeh describes the visual characteristics of the portions of a photograph that aren’t in focus. Though the term is often reserved for describing the out-of-focus specular highlights, it can be used equally to describe the qualities of out-of-focus middle tones and shadow areas of a photograph.
The proper pronunciation of bokeh is “bo,” as in Bozo, and “keh,” as in Kennedy. If you hear somebody saying “bokay,” as in bouquet, gently inform them they are describing a cluster of flowers.
Photographs © Allan Weitz, 2019

Good Bokeh and Bad Bokeh
Depending on the lens, the lens aperture, the size of the camera sensor, and the camera-to-subject focus distance, the characteristics of the lens’s bokeh can be described as “good” or “bad” bokeh.
The difference between good and bad bokeh boils down to how rounded, or natural looking the bokeh appears, which is greatly determined by the shape of the lens aperture, which in a perfect world, should be as rounded as the pupils in our eyes. The rounder the lens opening, the rounder, or more natural looking the specular highlights appear in your photograph.

Catadioptric, or mirror lenses produce circular, donut-shaped specular highlights, which photographers either love or hate. Generally, most photographers dislike the donut-like bokeh created by mirror lenses. (Personally, I’m OK with them.)

If you want to dig deeper into bokeh, check out this Explora article: Understanding Bokeh.
What’s your take on the topic of bokeh? Is bokeh something you take into consideration when choosing lenses or when taking pictures? Let us know your thoughts on the topic in the Comments field.
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