Making the Most of Your Photo's Bokeh

Photographers spend a lot of time eliminating blur from their photos. Auto-focus, vibration reduction, tripods... all of these things help us get sharper images. But blur can be good too--especially in the background, so we can lead the viewer's eye back to the subject in the foreground. Last week, in "," I explained that blur itself comes in different flavors. This quality, known as bokeh, makes some blur more aesthetically pleasing than others. This week, let's wrap up the discussion of blur and bokeh with some tips on how to vary and improve the blur in your own photos.

As I explained last week, bokeh refers to the character of the blur itself, which generally means the shape and crispness of the blurry elements. The blur in your photos is affected by the lens--primarily, the design of the optics and the aperture.

The result is that you can actually see the shape of the lens aperture in your blurry backgrounds (especially in light sources and reflections). Of course, lenses tend to be round, so these blurry spots are generally round as well--but they can be geometric, depending upon the number and arrangement of blades in the lens aperture.

Of course, you've probably figured out by now that you can't do much about the overall quality of the bokeh created by your lens. Your lens is constructed a certain way. It has a given number of blades, for example, and the blades have an unalterable shape that contributes to the bokeh (as well as the optics of the glass elements). You can't open up the lens and change the blades to modify the look of the blur.