Choosing your first digital signage display can be a daunting prospect given the huge variety of displays available ranging under 2″ to over 100″ and with differences in brightness, contrast ratio, aspect ratio, viewing angle, display technology, connections, mounting options and, of course, price.
In general you want the largest, brightest display with the greatest possible viewing angle but often you can’t find everything in one display and you have to chose which attributes to favor. This article discusses each attribute and helps you decide what to purchase.
Although bigger is normally better, sometimes a smaller display may be better suited to a particular location like counter top in a doctor’s office, pole-mounted mounted next to a cash register or attached to a shelf in an aisle. Sometimes it can be more effective to put multiple smaller displays closer to the products they are promoting rather than having one larger display trying to promote multiple products.
LCD display
Most modern screens have an aspect ratio of 16:9 (widescreen) although 4:3 monitors are still common and many computer monitors have slightly different ratios like 16:10. Some display manufacturers are starting to create novel displays with unusual aspect ratios like the LG M3800S-BN display which has a very wide format making it ideal to squeeze into a narrow space on a wall such as above a bar or cabinet. The most important thing is to ensure that your chosen display type and orientation is supported by your digital signage software so that it can create content that fills the display with no black bars and no distortion.
Most digital signage software also supports displays that have been rotated 90 degrees to the left or right. This can be a great way to maximize screen space on a narrow wall like in an entrance lobby. It also makes for a good poster format for content more suited to an arrangement like that, for example, a menu. But before you try mounting a display in a rotated configuration you should make sure it has good viewing angles in that orientation (more on that below).
A high-brightness display is particularly important if your chosen location is subject to sunlight or bright lighting. Many consumer-grade displays simply aren’t bright enough for the average retail or storefront location and you’ll want to look at brighter industrial-grade displays for such locations.
Contrast ratios and black levels are important but less critical for digital signage than, say, a screen to show movies on. Typically you will design your content to ensure that your text has very high contrast against the background image or video and that makes the absolute blackness or final contrast less important than a screen for watching movies.
Viewing angle, on the other hand, is much more important for digital signage than for regular TV watching because your audience will often be off-axis and moving around rather than sitting still directly in front of the screen as they would be at home. You want as wide a viewing angle as possible to ensure that people can read your messages even if they are viewing the screen at an oblique angle. 180 degrees is clearly the theoretical best viewing angle possible since it means anyone in front of the screen can see it but typically you’ll find screens claiming around 140 to 160 degrees. The quoted viewing angle is however somewhat meaningless as most manufacturers use the angle at which the contrast ratio is 10% of the on-axis contrast… that’s barely enough to see let alone to communicate your message clearly. Most LCDs have a ‘realistic’ viewing angle for digital signage of around 30-40 degrees from either side of on-axis.
Viewing angle is normally quoted only for the horizontal direction because screens are typically mounted at eye-level and everyone in the room is at the same level. But if you are mounting your screen high up, or if you mount it in a 90 degree rotated orientation (portrait instead of landscape) you need to worry about the vertical viewing angle. Since this number might not be available for your chosen screen the only way to find out is to try it or to ask before purchasing.
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