Stuff's Guide to Photography: What is bokeh – and how do I get it?
So, “bokeh”: a Japanese word that has no English equivalent, but once explained a very simple concept for any camera-wielder to grasp. How simple? Well, this five-step guide will clue you in on all the blurry basics.
There is both “good” and “bad” bokeh
"Good" bokeh courtesy of Sony's STF lens
Each lens’ characteristics – namely lens aberration and the shape of its aperture – determine the sort of bokeh it creates. Curved aperture blades, for instance, help create bokeh that looks more circular and, to most eyes, more pleasing – there are even lenses like Sony’s STF 135mm F2.8 and Nikon’s 105mm DC-Nikkor that are designed specifically to produce beautiful buttery smooth bokeh. Using a lens with fewer or straighter aperture blades can result in bokeh that’s more angular and “ugly”.
Image credit: Jerome Marot
The wider the aperture, the more likely you are to get bokeh
A wide F1.7 aperture setting is responsible for the bokeh here
Bokeh occurs when portions of the image are in front of or behind the in-focus area, and the easiest way to achieve this narrow depth of field is to use a lens with a wide aperture: F1.8, F2.0, F2.8 etc. Alternatively, you can use a longer, lower aperture lens – let’s say an 18-55mm kit zoom set at 55mm and F5.6 – and ensure the distance between subject and background is extensive.
Compacts and smartphones can achieve bokeh – but it’s tough
Bokeh in a macro shot taken with a Canon Powershot G15 compact
Because of their tiny apertures, it’s difficult to get bokeh in shots taken with point-and-shoot and smartphone cameras. The only way to achieve “real” bokeh with most is to take a macro (i.e. a shot of something very close to the lens), which will likely result in a blurry background and sharp, in-focus subject.
Image credit: Intensivtäteraggressor
There are some software tricks, however…
Android KitKat's camera does a passable job of creating fake bokeh
Many small cameras can use technical trickery to create fake bokeh. Android 4.4 KitKat’s camera, for instance, uses a clever algorithm to simulate bokeh, but requires that everything in the frame remains still for a few seconds. Most of these techniques can’t match the effect of real bokeh, but can deliver decent results in a pinch.