A picture is worth a trillion operations

This morning’s Observer column:

If you’re a keen photographer (which this columnist is) one of the things you prize most is a strange property called bokeh. It’s the aesthetic quality of the blur produced in the parts of an image that are not of central interest – the way a lens renders out-of-focus points of light. You often see it in great portraits: the subject’s eyes are razor-sharp but the – potentially distracting – background is fuzzy.

In the era when all photography was analogue, the only way to get good bokeh was to use lenses that produced narrow depth of field at wide apertures. Since the optical performance of most lenses decreased at such apertures, that meant that serious photographers faced a trade-off: their lust for bokeh involved compromising on overall image quality. And the only way round that was to spend money on lenses of complex design and exceedingly high optical quality. Neither of these came cheap: a photo-buff of my acquaintance, for example, recently laid out a small fortune for a Leica Noctilux f0.95 aspherical lens, which, its manufacturer claims, provides “unique bokeh”. (At a retail price of £9,100 it jolly well ought to.)

Enter Apple, which was once a struggling computer company…

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