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Japanese term, pronounced BO-KEH in English, used to describe the out of focus quality of a lens. Noun derived from the active verb "bokasu" which means to befog, to gradate, to render opaque, to smudge or render out of focus. It is usually the out of focus portions of the picture which distinguish the "look and feel" or "signature" of different types of lenses. The ideal boke for portraiture is a soft edged rounded blur with the brighter part towards the center of the blur disk.
Classic boke is that of legendary lenses like the 105mm f/2.5, 85mm f/1.4 and the more modern 105mm f/2D DC AF Nikkor