Autumn bokeh

Bokeh is a Japanese-originated photographic concept pertaining to the quality of the out of focus area of a photograph. I am also Japanese-originated, but I digress. Many photographers have some pretty strong feelings about what may be considered “good bokeh” or “bad bokeh.” I am only now coming to understand what the fuss is all about.

Basically I am in the camp of “if it looks good to me, it must be OK.” From what I’ve gathered so far, however, it’s the out of focus points of light in a photo’s background that reveals the quality of the bokeh and, by association, the quality of the lens being used. These out of focus points of light are called “circles of confusion” and are not to be confused with the sometimes out of focus writing at Points of Light.

Some lenses render fuzzy points of light with a brighter core that fades toward the edge while others render a brighter outer ring that fades toward the center. Still others render a rather flat point of light. One optics expert suggests that lenses that render “bright core” circles of confusion produce more pleasing bokeh than those that render “bright ring” circles or flat circles. He also tested a number of lenses and discovered that even in a single lens, bokeh may change depending on aperture, focal distance and the direction of both direct and reflected light entering the lens. As if circles of confusion weren’t confusing enough.

If you are losing sleep at night not knowing the bokeh-bilities of your favorite lenses, you can test them thusly: poke a pinhole in a piece of black paper (try to make the hole as uniformly round as possible), illuminate it from the back and take some photos at various angles and focal distances, then analyze the resulting photographs.

My 135mm 2.8 prime Nikkor lens, which I used for the above photo, produces the coveted “bright core” circles of confusion at the closest focal distances and maximum aperture opening. Yay for me. Not bad, considering the lens was given to me by a friend after he purchased it on eBay for about ten bucks. Way to go, John.

Now that I've thoroughly confused you about circles of confusion, you may now focus on the photo above.

Click on picture to enlarge. Photograph © 2007 James Jordan.