11 mrt. 2020

About pixel pitch and viewing distance for LED walls

LED 4 min om te lezen

If you are looking for a new LED video wall, chances are that you are being overwhelmed with technical jargon and marketing superlatives claiming the finest pixel pitches and the highest resolutions. But what is a pixel pitch and how is choosing the right pixel pitch important for the success of your display?

What’s the best pixel pitch?

Let's be clear on this: there is no such thing as the best pixel pitch! You could think that the decision is easy by just going for the display with the finest pixel pitch and the best resolution, but it is not as simple as that.

Different applications ask for different pixel pitches. If you want to know what pixel pitch to choose for your project, here are three important parameters to keep in mind.

#1 Pixel pitch and optimal viewing distance

For starters, it is key to find the optimal viewing distance (OVD) for your videowall. When looking closely at an LED module you can see the different pixels as clearly defined blocks. Taking a step back, the outlines of these blocks will start to blur and scatter. The OVD of your display is the distance from which you can no longer distinguish the individual pixels but start to see a uniform reproduction of the content instead.

Small pitches allow for the optimal viewing distance to be shorter. The smaller the pixel pitch, the closer the LED clusters are positioned on the module and the sooner the outlines of the blocks will start to blur. In boardrooms, for instance, where viewers sit closer to the LED screen, you might want to opt for a fine pitch LED display with a pixel pitch well below 2.5mm.

Large pixel pitches, on the other hand, are perfect for long distance viewing experiences like concerts or digital signage advertisements on buildings. Think of the legendary outdoor LED billboards at Times Square.

The animation below shows the recommended distance for the most used pixel pitch options.

Small pitches allow for the optimal viewing distance to be shorter. The smaller the pixel pitch, the closer the LED clusters are positioned on the module and the sooner the outlines of the blocks will start to blur. In boardrooms, for instance, where viewers sit closer to the LED screen, you might want to opt for a fine pitch LED display with a pixel pitch well below 2.5mm.

Large pixel pitches, on the other hand, are perfect for long distance viewing experiences like concerts or digital signage advertisements on buildings. Think of the legendary outdoor LED billboards at Times Square.

The animation below shows the recommended distance for the most used pixel pitch options.

Viewing distance gif explained led

Now if you know where your spectators will most likely be positioned in relation to the LED display, you can use the following rule of thumb to define the ideal pixel pitch your project needs:

This is a really handy rule of thumb that applies to most cases, but critical applications might need an on-site evaluation to be 100% sure. For example, in control room applications, such as SCADA or content with small letters, the OVD can increase.

#2 Size matters

Let’s say you’re looking for an LED solution to bring 4K brand content to life in your corporate lobby. 4K refers to a display resolution of 3.840 x 2.160 pixels, and has become the standard for home tv screens (you probably know the term 4K TV). 

#3 Money, money, money

Pricing is a 3rd factor that should not be overlooked. The total production cost of the final LED product relates exponentially to the LED density: a fine pixel pitch has more tiny LED pixels on the module. So, more diodes, more wiring and an increased manufacturing process. It all results in a higher production cost, and ultimately an overall higher purchase cost for you as a customer. In addition, more pixels also potentially entail more maintenance. In other words, if viewers don't sit too close to the LED wall, you can opt for a lower pixel pitch.

Conclusion

In conclusion, the ideal solution will always combine application objectives and budgetary considerations.

  • Always take into consideration the viewing distance of your audience. Short distances ask for fine pixel pitches; whereas higher pitches are perfect for long viewing distances.
  • Think about the required content resolution, but also about the available space as the pixel pitch defines the number of tiles you need to construct native resolution video walls.
  • Choosing a pixel density that’s too high for your specific set-up will not bring any visual advantage, and just needlessly increase the cost of your display.

Armed with this knowledge, you can now select your optimal LED video wall solution. Don’t hesitate to get in touch with your Barco expert to discuss the best option for your specific LED project.