If you think about the key attributes of high-quality lenses, sharpness is probably one of the first things that springs to mind. But for portrait and still-life images, bokeh can be even more important. This is a term for the pictorial quality of defocused areas within an image. Ideally, photographers look for a really soft and creamy appearance to blur fussy backgrounds and make the main point of interest really stand out.
The first thing you’ll need in the pursuit of beautiful bokeh is a tight depth of field. ‘Fast’ lenses with a wide aperture rating are therefore the order of the day, and a longer focal length is helpful. When shooting on a full-frame camera, 85mm lenses with an aperture rating of f/1.4 or f/1.8 are often preferred, some of which we covered in a group test back in issue 220. This time, we’re going further still, looking at Canon 85mm f/1.2 lenses (old and new), along with 105mm f/1.4 lenses from Nikon and Sigma.
But there’s more to beautiful bokeh than just a tight depth of field. Although lenses with matching focal lengths and aperture rating technically give an identical depth of field, the quality of bokeh can be very different in terms of smoothness - both for defocused areas and in transitional regions between in-focus and out-of-focus points.