Readability issues
As mentioned, maintaining stable surface and interior temperatures will help integrated LCD panels function at their peak performance levels, providing optimal readability. People’s eyes notice visible light sources as luminance/brightness and perceive images as differences in shades, so to be seen clearly, LCD panels selected for outdoor digital signage systems need to be both high-brightness and high-contrast.
For the best results in direct sunlight, a screen should be able to operate continually at a minimum luminance of 1,500 nits in bright sunlight. That said, lower luminance levels—e.g. 700 nits—with high contrast levels may still delivery clear readability, if properly integrated into the unit design.
It is important to be careful. The technical specifications for LCD panels’ contrast levels can be slightly misleading, as they are measured for displays in a pitch-black room, rather than in a real-world outdoor environment where ambient light reflecting off the screen will reduce the perceived differences between the brightest and darkest pixels.
Direct exposure to solar radiation, with light reflecting directly from the screen, is especially problematic. Around noon on a sunny day, daytime illumination can reach 96,000 nits, even without taking into account other objects in the vicinity reflecting further light onto a screen.
With this in mind, a screen’s high-brightness and -contrast performance should be supported with a high-quality anti-reflective glass treatment. This will help ensure images remain comfortably viewable—and text readable—throughout the day.
Outdoor digital signage must be specially engineered to withstand the negative effects of snow, moisture and dust, among other factors.
Careful investments
With these factors and conditions in mind, it is often worthwhile to invest in rugged technologies from the start, so the digital signage will last longer in the field. Today, state-of-the-art systems are available with a three-year guarantee. And they should last even longer—some have operated in Europe now for more than five years, in climates comparable to Canada’s.
That is not to say no maintenance will be required during the deployment period of three or more years. Rather, a realistic initial budget should allot some funds for occasional maintenance and account for ‘emergency interventions.’ When a system is down, the immediate attention required can prove expensive if not covered by the guarantee.
Also, compared to indoor digital signage, outdoor systems demand more product research, as even when they integrate the same components, their real-world performance can vary greatly from one location to another. It is important to test demonstration models, checking their performance in direct sunlight, and vital to understand exactly how systems are warranted with respect to other ambient factors.
For that matter, it is all the more important compared with indoor installations to determine (a) if it will even be possible to install digital signage at the intended outdoor location and (b) if so, how much it will cost to do so. Regulations will vary and bureaucracy can delay installation and other processes for long periods.
When well-placed in a suitable environment, however, outdoor digital signage systems can prove highly successful in enhancing communications with locals and visitors and in improving sales and marketing campaigns, to the point where they may more than pay for themselves. Further, some cities’ tenants and clients value capabilities of outdoor digital signage for catching the attention of younger people, attracting new customers and presenting themselves as innovative and progressive, to the point where these factors comprise a viable sales proposition. With this in mind, it could be even more costly not to consider outdoor installations than to move ahead with them.
David Dumouchel is director of communication for Montreal-based Diopso, which provides indoor and outdoor digital signage systems and related software. For more information, visit www.diopso.com or contact the company via e-mail at info@diopso.com.
