LED or LCD digital signage – which is best?

A few years ago, LED digital signage was a bit of a novelty. Definitely niche. It produced bright and exciting images and was flexible in terms of format, but the image quality was poor and the price was high. But now the equation has changed – LED’s have come down in price and the image quality and resolution have improved significantly – so making a choice between LED and LCD comes down to the requirements of your specific application. There is no such thing as ‘best’.

The five key factors to consider are:

• Cost / budget
• Resolution / pixel pitch
• Viewing distance
• Content format and aspect ratio
• Specific operating environment including ambient light

The main difference between LED and LCD is that LCD comes in specific dimensions and aspect ratio (normally 16:9) whereas LED displays are made up of modules that can be made up into any size, shape or aspect ratio. This means that LED displays can be custom-built for a particular site or to match the format of the specific content that it will need to display – just like building LEGO. LED displays can even be curved which can look quite dramatic, particularly on a larger scale. So generally, LED displays are more flexible than LCD.

Video walls have traditionally been made by bringing together multiple LCD screens into a single display, eg, a 2 x 2 video matrix, 3 x 3, etc. The limitation here is that bezel or frame around each screen creates black lines across the video wall. And although bezel width is reducing, this effect isn’t always optimal. LED’s are built as a single unit, so there are no bezel lines across the screen which offer definite advantage. The impact of the LCD bezels is less for video content, but for static content, unless the content is formatted correctly, the black lines of the bezel may break up the content in an unpredictable way – for example, making text difficult to read.

The other thing to consider is while LCD signage is usually less expensive, it is most economic at smaller screen sizes which are obviously made in higher volumes. As LCD screens get larger, they get relatively more expensive, so as screens get to 95” or larger, LCDs become less cost-effective and LED becomes a genuine choice based on cost alone.

LCD screens normally have a higher resolution (smaller pixel pitch), but there are a couple of considerations here. LED resolution has improved a lot. In fact, micro-LED is available with a pixel pitch of less than 1mm, but the cost rises quickly as the resolution improves, so the sweet spot for LED resolution is a pixel pitch of around 2 – 2.5mm. The resolution also needs to be understood in relation to the viewing distance. For example, close viewing requires a higher resolution, but for longer viewing distances, resolution becomes less relevant. Generally, LCD is better for close viewing.

The specific location of the Digital Signage and more importantly, the ambient light, impacts the choice between LED and LCD. LED is brighter and more effective where there is a lot of ambient light, including external locations. In addition, the brightness of the LED can be automatically adjusted in relation to the ambient light which optimises the image quality and reduces power. For larger displays, video walls or outdoor installations, LED is often the most practical solution and in some instances, the only solution.

There is a multitude of suppliers of LED displays and it’s possible to trade off quality, cost, warranty and support.

Generally, I would recommend a quality A-class option as this will most likely be the best value in the long run. An A-class display normally comes with a 10-year warranty, but it is possible to choose a one or three year warranty combined with a lower purchase price. When considering cost, you also need to consider what sort of support you get. There are lots of lower-cost LED’s coming onto the market, but the quality is low and they have no local support, so if anything goes wrong, you’re on your own.

So the LED v LCD decision isn’t clearcut anymore. The good news is that both are good options, you just need to make a decision based on your particular circumstances. The starting point should be your communication and marketing strategy and the content you have to support this. Then you can design the technology solution based on the specific characteristics of LED and LCD.