---

Bokeh (Photography)

Bokeh (pronounced /ˈboʊkə/ BOH-kə or /ˈboʊkeɪ/ BOH-kay) is a term derived from Japanese, used in photography to describe the aesthetic quality of the blur in the out-of-focus areas of an image. It is not merely the presence of blur, but the visual character of that blur, which is influenced by the lens’s optical design. Bokeh is often a subject of technical and artistic consideration, especially in portrait, macro, and telephoto photography.

Contents

1. Etymology and History
2. Technical Basis
3. Characteristics of Bokeh
4. Influencing Factors
5. Artistic Application
6. See Also
7. References

1. Etymology and History

The term originates from the Japanese word “boke” (暈け or ぼけ), a noun form of the verb “bokeru” (暈ける or ぼける), meaning “to blur” or “to be out of focus.” The concept gained specialized meaning in Japanese photographic circles during the late 20th century.

Photographers and lens reviewers, particularly in Japanese magazines like Photo Technic, began using the compound term “boke-aji” (ボケ味)—where “aji” (味) means “taste” or “flavor”—to critique the qualitative aspects of a lens’s out-of-focus rendering. This distinguished between merely being out of focus (boke) and the subjective quality of that blur (boke-aji).

The term was formally introduced to the English-speaking photographic world by editor Mike Johnston in the March/April 1997 issue of Photo Techniques magazine. He transliterated it as “bokeh” to suggest the correct Japanese pronunciation to English speakers, thereby importing the nuanced concept of judging the “flavor of the blur.”

2. Technical Basis

Bokeh occurs in parts of an image that lie outside the depth of field (DOF). While depth of field defines the zone of acceptable sharpness, bokeh describes the appearance of elements in the unacceptable sharpness zones.

The quality of bokeh is primarily determined by the lens’s optical aberrations and the shape of its aperture diaphragm. A lens that is well-corrected for spherical aberration typically produces smoother, more pleasing bokeh. The design of the aperture blades influences the shape of out-of-focus highlights, known as “bokeh balls.”

3. Characteristics of Bokeh

Bokeh is often qualitatively categorized by photographers:

• Good / Pleasing Bokeh: Described as “smooth,” “creamy,” or “buttery.” Out-of-focus transitions are gradual, and highlights appear as soft, rounded discs without sharp or distracting edges. The background is unobtrusive, allowing the subject to stand out clearly.
• Bad / Harsh Bokeh: Described as “busy,” “nervous,” or “distracting.” It may feature hard-edged geometric shapes (from the aperture), double lines (“onion-ring” patterns from lens element molding), or a generally chaotic texture that competes for the viewer’s attention.

4. Influencing Factors

Several factors determine the bokeh characteristics in a photograph:

1. Lens Optical Design: The most critical factor. Prime lenses, particularly those with wide maximum apertures (e.g., f/1.4, f/1.8), and lenses with more rounded aperture blades are often prized for their bokeh.
2. Aperture Setting: Shooting at the lens’s maximum aperture usually produces the most pronounced and characteristic bokeh. Stopping down can make the aperture shape (e.g., heptagonal) more visible in highlights.
3. Focal Length: Longer focal lengths (telephoto lenses) compress perspective and produce a shallower depth of field at a given aperture, enhancing the prominence of the out-of-focus areas.
4. Subject-Background Distance: A greater distance between the in-focus subject and the background increases the blur, making the bokeh quality more apparent.
5. Background Texture: Backgrounds with small, bright points of light (e.g., city lights, sunlight through foliage) most clearly reveal the shape and texture of the bokeh.

5. Artistic Application

Bokeh is used as a deliberate compositional tool to:

• Isolate the Subject: By softening the background, the photographer directs the viewer’s attention solely to the main subject.
• Create Depth: It enhances the three-dimensional feel of a two-dimensional image by separating foreground, subject, and background.
• Evoke Mood: Smooth bokeh can convey a sense of romance, calm, or professionalism, while harsh bokeh might be used for a more chaotic or gritty aesthetic.
• Simplify Composition: It can turn complex, cluttered backgrounds into simple washes of color and light.

The pursuit of “good bokeh” has influenced lens design and marketing, with many manufacturers highlighting the bokeh characteristics of their portrait and premium lenses.

6. See Also

• Depth of Field
• Aperture
• Lens Aberration
• Portrait Photography
• Mike Johnston

7. References

1. Johnston, M. (1997). “Bokeh: What is it? What makes it good or bad?” Photo Techniques, 18(2).
2. Photo Technic (Various Issues, 1990s). Technical lens reviews. Nippon Shashin Kōgyō Shuppan.
3. Bokeh.” Wikipedia, The Free Encyclopedia. Retrieved from relevant Wikipedia entry.
4. Van Walree, P. “Bokeh.” On Paul van Walree’s Photographic Optics. (Technical online resource).

(Disclaimer: This is a simulated Wikipedia-style entry for informational purposes. For the canonical source, please visit the actual Wikipedia page on “Bokeh.”)