15.07.2010
View outdoor LED Screens and LED Displays
1. What dimension will your LED screen display or LED sign be that you want to install?
The size of the outdoor LED screen displays and LED signs are very important to know to determine the resolution per square meter we have to set for the screen. This is to avoid low quality video with very little detail or a very high quality video that is not necessary (in some cases it depends on the customer´s project type). The variable that decides the LED screen resolution per square meter is called the pixel pitch, which tells us the distance between the LED´s in millimeters. The shorter the distance of the LED´s, the higher the screen resolution per square meter, and a greater distance, the resolution will be less.
In other words, small LED screen displays require a higher resolution per square meter to achieve complete resolution of the screen (Our recommendation would be a minimal of 43,000 pixels for video standard quality without losing detail) and among the largest LED screen displays less resolution m² is needed to reach a total of 43,000 pixels resolution.
Remember that LED screen displays that will show videos with a normal quality standard must have a minimall of at least 43,000 physical pixels (or real pixels) in total, and high definition LED display screens at least a total of 60,000 physical pixels (or real pixels). If you require a glarge LED screen display where the closest viewing distance is very small, 8 meters for example, we recommend LED screen displays with virtual pixels. With virtual pixels, the number of physical pixels will be multiplied with a factor of 4. This means that if a LED display screen has a total of 50000 physical pixels has a total of 200,000 virtual pixels. The minimal viewing distance will be half of the distance of a LED screen display with real pixels.
2. What will be the minimal viewing distance from your LED screen display to the closest spectators?
The minimal viewing distance is the distance from where the closest pectators will be viewing the LED display and the LED screen display itself, taking the hypotenuse (a hypotenuse is the longest side of a right triangle, the side opposite of the right angle) in this case. How can we calculate the hypotenuse? It's easy; the length of the hypotenuse of a right triangle can be found using the Pythagorean theorem, which states that the square of the length of the hypotenuse equals the sum of the squares of the lengths of the two other sides. That means H² = L² + A², and in practice would be as follows: if H = Hypotenuse, L = Length, A = Altitude:
We want to set a screen at a height of 12 meters where the nearest spectator will see the screen from a distance of 5 meters. The calculation would be following:
H² = 5² + 12² ⇒ H² = 25 + 144 ⇒ H² = 169 ⇒ H = √169 ⇒ 13 meters.
So we need to find a LED display screen of 15 sqm with a configuration that will give us a minimal viewing distance of approximately 13 meters.
3. What will be the total resolution of the LED screen display?
To find out if we have the right configuration for your LED screen display, that will show videos of normal quality or high-definition videos, we have to make another kind of simple calculation. In point two we mentioned an important point about showing videos with a normal standard definition, where we consider a screen with at least 43,000 pixels, or a screen with a high-definition video, with at least 60,000 pixels or more. Now we have to calculate this, the calculation is as follows: the total size of the LED screen display multiplied by the resolution per square meter of the configuration you chose with point 2.
For example, if we want to install a 15 square meter LED display screen, and the closest viewing distance is 13 meters (like we calculated in point 2) we can choose a LED display screen of 16mm with physical pixels and virtual pixels, or 20mm with virtual pixels. Why 16mm real pixel and 20mm virtual pixel? Because the closest viewing distance of these configurations are about > 15 meters. So in this case, (1) for the 16mm real pixel LED display the total number of physical pixels is 3,906 per sqm, (2) for the 16mm virtual pixels 3,906 x 4 = 15,624 total virtual pixels, (3) and for the 20mm virtual pixel LED display it will be 2,500 physical pixels per sqm x 4 = 10,000 virtual pixels per sqm. So the final calculation will be:
- 16mm real pixel: the total resolution of the LED display screen will be 15 sqm x 3,906 = 58,590 total real pixels
- 16mm virtual pixel: the total resolution of the LED display screen will be 15 sqm x 15,624 virtual pixels = 234,360 total virtual pixels;
- 20mm virtual pixel: the total resolution of the LED display screen will be 15 sqm x 10,000 virtual pixels = 150,000 total virtual pixels.
Conclusion: The LED display screen with the most benefith will be the 20mm virtual pixel LED display screen because of it´s price, quality and viewing distance. Although if you require a higher quality LED display for showing high quality videos, of course we recommend then the 16mm real pixel LED display because of the viewing distance and the total quantity of physical pixels which is around 60,000 pixels, but of course the price will be higher than the 20mm virtual pixel LED display. Real pixel LED displays are always better than virtual pixel LED displays.
4. Choosing the LED screen display that correspond to your expectations
With the examples we have shown in points 1, 2 and 3 our LED screen display configuration will be a 15 sqm with a closest viewing distance of 13 meters and a resolution of 10,000 virtual pixels per sqm (the electronic LED display screen will be showing normal quality video). Looking at the table below, there are only two options for us, which are:
- A LED screen display with 16mm real pixels (DMX-PH16-RGB-E); this configuration is for LED screens with a dimension bigger than 11sqm (recommended by DMX). Besides that LED screens displays has a viewing distance from 15 meters and more, which is about what we calculate (13 meters we calculated), and 15sqm x 3906 pixels per sqm = 58,590 pixels in total (aprox.) which is more than what we need but the quality and definition will be very high.
- A LED screen display with 20mm virtual pixels (DMX-20V-RGB-E): this configuration is for LED screens with a dimension bigger than 15sqm (recommended by DMX) which is equal to what we want to configure. Besides that LED screens displays has a viewing distance from 15 meters and more, which is about what we calculate (13 meters we calculated), and 15m² x 2500 pixels/m = 37,500 real pixels in total, and 37,500 x 4 = 150,000 virtual pixels (aprox.) which is more than what we need but the quality and definition will be very high.
View outdoor LED Screens and LED Displays