Master your DSLR: Bokeh
IT’S NOT JUST THE SHARPNESS OF A LENS THAT MATTERS, BUT HOW IT HANDLES BLUR, TOO.
[ TECHLIFE TEAM ]
EVEN IF YOU’RE a newcomer to photography, you’ve probably heard the word ‘bokeh’ being bandied around. Bokeh, which is pronounced ‘bouquet’ or ‘bow-kay’ by people in the know, is used to describe the blur in a picture. Not its quantity — that’s something determined by the choice of aperture, focusing distance, focal length and more — but rather its quality. It’s a hard one to quantify as it can’t be measured in the same way that, say, sharpness can. It’s also somewhat subjective: bokeh that one person judges to be beautiful might cause another to recoil in horror.
That being said, there are some common terms used to describe the look of out-of-focus areas in a picture — busy, nervous, soft, creamy, harsh, jittery — and the way in which out-of-focus areas are rendered in an image is something to consider when weighing up the pros and cons of a lens.
Bokeh and depth of field go hand in hand: the shallower the depth of field you choose is, the more pronounced the out-of-focus areas in a picture become. This is why the way in which a lens designed for portraits and close-ups — types of photography where large apertures are often used creatively to separate the subject from a background or foreground — draws its bokeh is more important than it is for a wide-angle lens designed for landscape photography.
To maximise bokeh, you need to use long lenses at large apertures, get close to the subject and make sure the background is far enough away to be rendered as a soft blur. Shooting in the right light is as important as ever, too: taking photos under a midday sun on a clear day is unlikely to give you the smoothest, softest bokeh. The harsh, direct light will produce harsh, distracting bokeh and any overly bright hotspots in the background, even if they’re blurred, will draw the viewer’s attention. It’s the lens that has the biggest impact on how pleasing the out-of-focus areas are, though. While some lenses produce more attractive blur than others, if you’re seriously bitten by the bokeh bug, then you might want to consider one of a handful of special-purpose lenses that are designed with bokeh control in mind, such as Nikon’s 105mm and 135mm Defocus Control (DC) lenses, Fujfilm’s XF 56mm f/1.2 R APD and Lomography’s retro-styled Petzval 58 Bokeh Control lens.