misfocus

Misfocus is the state in which an optical system or a cognitive process fails to align with the intended target, producing blurred imagery or misdirected attention. In imaging, misfocus occurs when the focal plane does not coincide with the subject, leaving parts of the scene soft or out of sharp focus. In psychology and human factors, misfocus describes a misallocation of attentional resources, which can lead to errors or delayed responses.

Optical misfocus

Causes include incorrect focusing distance, camera or subject movement, lens calibration errors, or autofocus failures. The result is a blurred image with a lack of edge clarity or smeared details, especially at the intended subject’s edges. In macro or portrait work, small errors can render the subject soft while the background remains visually dominant. Prevention involves careful focusing techniques: manual focus with magnification, using focus peaking, verifying focus with live view, stabilizing the camera with a tripod, and considering depth-of-field choices such as stopping down or using hyperfocal distance.

Cognitive misfocus

Causes include fatigue, distraction, high cognitive load, poor task design, or interruptions. Effects include missed cues, incorrect judgments, or slower performance. Prevention includes minimizing distractions, structuring tasks to reduce switching costs, training attention and perceptual skills, and employing design strategies that guide attention to relevant information.

See also: focus, depth of field, autofocus, attention, selective attention, perceptual load.