When discussing outdoor digital signage, brightness usually gets most of the attention. However, after working on several display projects, I've found that increasing brightness alone doesn't always solve readability problems. In many installations, reflected sunlight is a much bigger issue than insufficient luminance.
One technology that deserves more attention is high haze anti-glare (AG) glass.
Unlike a glossy glass surface that reflects light almost like a mirror, anti-glare glass uses a microscopically textured surface to scatter incoming light. Instead of producing a sharp reflection directly in front of the viewer, the reflected light is diffused across a wider area. This makes on-screen content much easier to see in environments where sunlight or strong artificial lighting cannot be controlled.
The term "haze" refers to how much transmitted light is intentionally scattered by the glass. A lower haze value keeps images crisp and vibrant but provides less glare reduction. A higher haze value produces stronger anti-glare performance, although it also softens the image slightly. Selecting the right haze level is therefore a balance between image clarity and outdoor visibility.
For indoor menu boards or displays in controlled lighting, a low-haze surface is often sufficient because image sharpness is the priority. Outdoor advertising displays, transit information screens, and self-service kiosks face a completely different challenge. They must remain readable throughout the day despite direct sunlight, changing weather, and reflections from nearby buildings or vehicles. In these situations, reducing glare is usually more valuable than preserving maximum image sharpness.
Another common misconception is that anti-glare glass and anti-reflective (AR) glass perform the same function. Although both aim to improve visibility, they work differently. AR glass reduces reflections through optical coatings, while AG glass diffuses reflections using a textured surface. For many outdoor digital signage applications, AG glass is often chosen because it offers durable glare reduction under demanding environmental conditions.
Of course, high haze glass is not a universal solution. Excessively high haze levels can reduce perceived contrast and make fine graphics appear slightly softer, particularly on high-resolution displays viewed at close distances. This is why display designers usually evaluate viewing distance, ambient lighting, content type, and installation environment before deciding on the appropriate surface treatment.
In practice, outdoor readability depends on the complete optical system rather than a single specification. Display brightness, contrast ratio, cover glass treatment, optical bonding, viewing angle, and enclosure design all contribute to how easily users can read the screen in real-world conditions.
I recently read a technical article that explains the optical principles behind high haze anti-glare glass, how haze values influence display performance, and why this technology is widely used in outdoor advertising displays and digital signage. It provides a useful overview for anyone interested in display engineering:
Reference: What is High Haze Anti-Glare Glass for Advertising Displays?
