Before you can even begin evaluating and choosing displays for a digital signage deployment, you have to determine some basic facts about your planned applications and environment.

First: What kind of content do you expect to predominate?

“You need to determine the anticipated the ‘dwell’ time,” says Mike White, CEO, Multi-Media Solutions, which does primarily digital signage for corporate accounts, along with for government and military locations. “That’s how long you expect someone to look at the content.”

Second, says White, “What is the primary type of content being displayed? This will influence the size of the display. For example, if it will be movie trailers, the screen can be smaller because the impact is recognized by the brain and our brain compensates. But if there will be text, the letters need to be big enough so they can be read and understood.

Third, “Determine the distance that a display will be viewed from, and the primary type of content being displayed, so that the digital signage can be effective,” says White. “The size of the display is a key factor; for example, I’ve seen digital signage in hotels where the content could not be read at the target distance.”

The basic visual guidelines for display readability, according to White —  which pre-date digital signage, dating back to the world of projection screens —  are 1-to-6/1-to-8/1-to-10. “The same rules apply,” says White. “If you can’t read it, you can’t read it.”

Depending on the nature of the content, says White, “Your screen should be one foot tall for each six, eight or 10 feet of viewing distance, meaning the furthest away you expect somebody to be reading or trying to absorb information from the screen.”

For example, says White, “1-to-6 is for ensuring spreadsheets, diagrams and other details are visible in a boardroom, network operating center, or other facility. 1-to-10 is for big venues like auditoriums, or a large church where most of the content is video plus large words for singing. 1-to-8 is typically good for digital signage where the content has to be read and understood, like in public transportation sites, keeping in mind that you also have to pay attention to the font size you choose.”

“If you have already decided how much content the screen will have on it, relative to words and images, and the majority of it will not be video-based —  and most digital signage is not —  work with someone that has an understanding of the math of readability,” says White.