Viewing angle: Difference between revisions

Revision as of 10:00, 17 July 2010

Revision as of 05:53, 31 October 2011

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In [[display device|display technology]] parlance, '''viewing angle''' is the maximum [[angle]] at which a display can be viewed with acceptable visual performance. In a technical context, this angular range is called '''[[viewing cone]]''' defined by a multitude of '''[[viewing cone|viewing directions]]'''.

The image may seem garbled, poorly saturated, of poor [[contrast ratio|contrast]], blurry or too faint outside the stated viewing angle range, the exact mode of "failure" being dependentdepends on the display type in question. For example, some [[projection screen]]s reflect more light perpendicular to the screen and less light to the sides, making the screen appear much darker (and sometimes colors distorted) if the viewer is not in front of the screen. Many manufacturers of projection screens thus define the viewing angle as the angle at which the [[luminance]] of the [[image]] is exactly half of the maximum. With LCD screens, some manufacturers have opted to measure the contrast ratio, and report the viewing angle as the angle where the contrast ratio exceeds 5:1 or 10:1, giving minimally acceptable viewing conditions.

The viewing angle is measured from one direction to the opposite, giving a maximum of 180° for a flat, one-sided screen. Some display devices exhibit different behaviour in horizontal and vertical axis, requiring users and manufacturers to specify maximum usable viewing angles in both directions. Usually the screens are aligned and used to facilitate greater viewing angle in horizontal level, and smaller angle in the vertical level, should the two of them be different in magnitude.