unscharf

Unscharf is a German adjective meaning "not sharp", "blurred" or "indistinct". It is formed from the adjective scharf ("sharp") with the negative prefix un-. Pronunciation in standard German is approximately [ˈʊnʃaʁf]. Comparative and superlative forms are unschärfer and am unschärfsten.

In everyday language unscharf describes visual indistinctness (a blurred photograph, an unclear image) or lack of precision in speech and thought (vague arguments, imprecise instructions). Synonyms include verschwommen and undeutlich; the opposite is scharf or deutlich.

Technical contexts give the term specific meanings. In optics and photography unscharf refers to images affected by defocus, motion blur, limited depth of field or aberrations; corrective measures include refocusing, image stabilization, or computational deblurring. In physics the related noun Unschärferelation is the German name for Heisenberg’s uncertainty principle, emphasizing limits on simultaneous precision of certain measurements. In computer science and mathematics the adjective appears in translations of fuzzy concepts (unscharfe Mengen, unscharfe Logik), where it denotes graded membership or partial truth rather than binary delineation.

As a lexical item, unscharf is widely used in both literal and figurative registers, and it appears in compound and noun forms (Unschärfe) to denote the state or degree of lack of sharpness.