What is Pixel Pitch?
In the world of LED wall displays, one term that often arises is ‘pixel pitch’. It’s an important specification to understand as it directly affects the quality of people’s visual experience when looking at your display.
As you may already know, LED walls are composed of numerous tiles containing hundreds of LEDs (light-emitting diodes) used to display your content. Pixel pitch refers to the type of tiles you use.
What is Pixel Pitch?
Pixel pitch is the distance between individual LEDs on a tile, which is typically measured in millimetres (mm).
A smaller pixel pitch means the LEDs (also known as pixels) are closer together, resulting in higher LED/pixel density and finer image quality. It produces sharp, vibrant visuals with smooth edges, providing a high-quality viewing experience.
Pixel pitch also determines how close you can get to the display without seeing the individual LEDs that form the images.
Pixel Pitch and Image Quality/Resolution
It’s crucial to also understand the relationship between pixel pitch and image quality/ resolution when purchasing an LED wall.
For large outdoor LED wall displays intended to showcase sales promotions to passing motorists, a lower level of detail is required, making a higher pixel pitch/lower pixel density appropriate.
However, if you aim to exhibit intricate graphics or high-definition videos, a smaller pixel pitch will be more suitable to ensure the content remains sharp and vibrant even when viewed up close.
So, how do you determine the necessary quality (and thus pixel pitch)? Simply put, to display high-quality visuals, your LED wall needs to have a sufficient number of pixels.
For ‘Standard Definition’ content, a display with a minimum of 640 x 480 LEDs/pixels is necessary. However, such a display wouldn’t be suitable for ‘Full HD’, which requires 1280 x 720 pixels. For 4K resolution, at least 3840 x 2160 pixels are needed.
To illustrate, if you have a small 2m x 2m display with a 4mm pixel pitch, you’ll have enough LEDs for Standard Definition content but insufficient LEDs for displaying 4K content.
How To Calculate The Pixel Pitch You Need
LED walls & minimum viewing distances
The pixel pitch needed depends on the size and intended resolution of your LED wall display, as well as the minimum and average viewing distances.
As a general rule of thumb, the minimum viewing distance is 1,000 times the pixel pitch. For example, with a pixel pitch of 2mm, the minimum viewing distance would be 2 metres, and so on.
Remember, this is the minimum recommended viewing distance, not the average distance. Therefore, you’ll need to consider the percentage of people likely to view the display at the minimum and maximum viewing distances and calculate the necessary pixel pitch accordingly.
Understanding Pixel Pitch Sizes
Different manufacturers produce LED tiles in various sizes, offering a wide range of options.
At one end of the scale, there are tiles with an ultra-small 0.5mm pitch now available. These are suitable for control room displays where staff need to monitor detailed images and where information clarity is paramount.
At the other end of the scale, there are tiles with a 16mm or even 20mm pixel pitch, appropriate for displays positioned high up on buildings, where viewers may be around half a mile away, such as on a nearby busy road.
Given the extensive variety in the market, it can be useful to have some context and know the most common pixel pitch sizes, as these will be available from more suppliers and easier to buy at competitive prices.
For standard displays where fine detail and high resolution are not critical, the most commonly used pixel pitches are 2.5mm for short viewing distances, 4mm for mid-distance, and 6mm for long distance.
LED Wall Cost
While there is no direct link between pixel pitch and hardware quality, it’s essential to be aware that one 2.5mm LED tile may not be the same as one from another supplier.
Due to their small size, the quality of LEDs can vary significantly. Manufacturers test and grade LEDs from A to Z. Reputable LED tile manufacturers like Samsung, HikVision, and LG will use LEDs with higher quality grading (e.g., B-D). Less reputable manufacturers will use LEDs at the other end of the quality scale. This is why purchasing LED wall hardware based solely on price can result in poor quality hardware that requires quick replacement.
It’s also worth mentioning that LED tiles, in general, are not very durable. If there is a chance of someone leaning on or brushing against your LED wall, steps should be taken to protect it. More robust LED tiles with a resin coating are available but tend to be more expensive.
Pixel Pitch & LED Tile Cost
It’s important to note that lower pixel pitches typically translate to higher costs for LED tiles. This is simply because higher pixel density requires more LEDs/pixels, which increases manufacturing costs. Conversely, when the pixels are more spaced out, fewer LEDs are needed for a single tile, reducing the manufacturers’ LED purchasing costs.
Therefore, it’s crucial to strike the right balance between image quality, viewing distance, and the budget available to avoid overspending or underspending and underspecifying or overspecifying your hardware.
Curved LED Walls & Pixel Pitch
If you’re creating a curved LED wall (concave or convex), the effect on pixel pitch depends on the degree of curvature.
Generally, the tightest maximum curve is currently 7.5%, and the finer the pixel pitch, the more gentle the curve needs to be. This is because the gap between the tiles becomes visible and disrupts the display. With larger pixel pitches, this gap is less noticeable since the pixels are already relatively far apart, making a small gap harder to see.
The Final Decision
Whether you’re considering a large-scale outdoor billboard or a small indoor display, purchasing and installing an LED wall display usually involves a significant investment, so getting it right the first time is important.
By understanding the importance of pixel pitch, you can make informed buying decisions and have confidence in them.
However, striking the right balance between the four factors of cost, viewing distance, resolution, and hardware quality is not easy. Therefore, we always recommend consulting at least one expert with plenty of experience in installing LED walls to get their recommendations.
If you would like our advice on the pixel pitch you need for your LED wall display, or if you already have a good idea and would like a quote for hardware supply and installation, please get in touch.
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