About pixels And pitches - 1 views
started by kbojezhang44 on 26 Mar 20
started by kbojezhang44 on 26 Mar 20
started by kbojezhang44 on 26 Mar 20
started by kbojezhang44 on 26 Mar 20
If you are looking for a new LED display, 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 is a pixel pitch?
First, let's go back to basics. How is an LED wall actually built? An LED wall is put together out of LED tiles, which in their turn consist of multiple LED modules. These LED modules contain LED clusters or LED packages, i.e. red, blue and green light emitting diodes (LEDs) grouped in pixels.
Pixel pitch is a technical specification that is used to differentiate between LED tiles. Note that the pixel pitch specification can also be used for other display technologies like LCD, but in this post we're only talking LED.
The pixel pitch is the center-to-center distance between two pixels, usually measured in millimeters. If you have a 10mm pixel pitch, it means that the distance from the center of one pixel to the center of the adjacent pixel is 10 millimeters. This results in low resolution and a grainier image quality. Tiles with lower pixel pitches have a smaller distance between two different LED clusters. That is less empty space and, thus, more pixels available on the LED module. This increased pixel density leads to high resolutions and more detailed content.
What's the best pixel pitch?
Let's be clear on this one. 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 are close to the screen you might want to opt for a fine pitch LED display with a pixel pitch 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.
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:
OVD (in m) = 2 * commercial pixel pitch (in mm)
Your ideal pixel pitch (in mm) is OVD (in m) / 2
#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. An LED display module with a 1.5 mm pitch has a higher pixel density, it can fit more pixels than for example a 2.5mm LED module on the same physical size. Hence, it has more pixels per module available to realize the 4K content. As a result, you'll need less modules to form a 4K display. Hence, the fine pixel pitch reduces the display size and keeps the physical space requirements to a minimum.
#3 Money, money, money
Pricing is a 3rd factor that shouldn't 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.
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 choose your LED pixel pitch.