The Low Light Photography Field Guide

Repair to Extend Focus

Although an image that is completely out of focus and nowhere near sharp is usually considered a reject (though not always), gradations of sharpness are an absolutely normal part of photography.

Because of the way the eye and brain work, we are only rarely ever conscious of this kind of optical blur in real life, as our gaze flicks rapidly from one part of a scene to another, refocusing almost instantaneously. Nevertheless, more than a century of looking at photographs has made depth of field (see definition) a normal feature of imagery. Particularly in a long-focus picture, it is completely acceptable to have blur at the front and back around a limited sharp zone, and even attractive.

Because low light shooting handheld ...