infocus

Infocus, or in focus, describes an optical state in which an image or object is sharp and well resolved by a lens system. When light from the subject converges at the image plane—typically a camera sensor, film, or a display—the resulting image presents clear edges and details. The concept applies across photography, filmmaking, microscopy, and vision systems.

Achieving focus involves adjusting the distance between the lens and the image plane or, in automatic systems, employing autofocus that analyzes image sharpness or phase differences to align with the focal plane. The degree of sharpness is influenced by depth of field, which depends on aperture, focal length, subject distance, and sensor size. Common focusing issues include front focus (subject appears too near the camera) or back focus (too far away), as well as overall softness when the focal plane does not align with the subject. Techniques to manage focus include manual adjustment, calibration of lenses, focus peaking aids, and focus stacking to extend depth of field.

Infocus is also a brand name used by several technology companies. The most widely known is InFocus Corporation, a manufacturer of projectors, displays, and related equipment marketed for business and educational use. Brand ownership and product lines have evolved through corporate restructurings and market changes.

In scientific imaging, precise focus is essential for measurement accuracy and reliable image analysis, whether in consumer cameras, professional optics, or microscopy, where coarse and fine focusing adjustments or automated focus routines are employed to ensure the subject lies on the focal plane.