daylightreadable

Daylightreadable refers to the quality of text and imagery remaining legible in bright outdoor daylight. The term is most often applied to electronic displays but also encompasses printed media designed for outdoor viewing. In practice, daylight readability depends on how well a device or material maintains contrast and minimizes glare under strong ambient light.

For displays, key factors include high luminance, strong contrast, and surface treatments that reduce reflections. Luminance is typically measured in nits (cd/m^2); outdoor devices often target higher brightness levels and adaptive brightness to preserve legibility in varying light. Anti-glare or anti-reflective coatings help minimize glare, while color accuracy and stable performance across lighting conditions contribute to readability. Some technologies, such as transflective LCDs, use ambient light to boost perceived brightness without excessive backlighting, while others rely on high-brightness backlights or emissive displays. E-ink and similar reflective technologies are renowned for daylight readability in static content, due to their low reflectance and natural ink-like appearance.

Evaluation usually involves measuring luminance, contrast, reflectance, and color fidelity under specified ambient illumination. Standards and testing procedures from industry groups assess outdoor readability in conditions that mimic direct sunlight and low-angle light to ensure consistent performance.

Applications span consumer devices (smartphones and rugged tablets), automotive instrument clusters, outdoor signage, kiosks, and e-readers. Trade-offs include power consumption, heat, cost, and potential color shifts at extreme viewing angles or brightness levels.

See also: display technology, outdoor signage, ambient light sensing, glare reduction.