In-depth analysis of LED display parameters: from basic to advanced Guide

Nowadays, LED display screens have been widely used in commercial advertisements, sports events, and concerts. However, facing the dazzling array of LED display screen on the market, how can we accurately understand their parameters? How to choose the LED display that best suits our needs? This article will comprehensively analyze the key parameters of LED display screens. We hope that you can better understand and choose them.

Basics: Core parameters of LED display screens

Pixel pitch

Pixel pitch, also known as dot pitch, is one of the most basic parameters in LED display screens, which directly determines the clarity and viewing distance of the screen. Pixel pitch refers to the distance between the center points of two adjacent pixels, usually expressed in millimeters (mm), such as P1.25, P2.5, etc. Smaller pixel pitch means more pixels per unit area, so they can present higher image resolution and more delicate picture quality.

Application scenarios: For example, P1.25 fine pitch LED displays are suitable for close viewing occasions, such as conference rooms, exhibition halls, high-end shopping malls, etc.; while  large pixel pitches LED displays (such as P10 and P16) are more suitable for outdoor billboards and stadiums due to their far distance.

Technical impact: Pixel pitch not only affects the display effect, but is also closely related to factors such as the cost, heat dissipation, and weight of the screen. With the continuous advancement of LED technology, the pixel pitch is gradually smaller, and LED displays are becoming more and more high-definition.

Resolution

Resolution is one of the important indicators for measuring the display effect of LED displays. It indicates the total number of pixels that the LED screen can display. Under the same area, the higher the resolution, the higher HD. Resolution is usually expressed in the form of “horizontal pixel count × vertical pixel count”, such as 1920×1080 (ie 2K), 3840×2160 (ie 4K), etc.

Module and cabinet resolution: 

Module resolution refers to the number of pixels of a single LED module – the number of horizontal pixels multiplied by the number of vertical pixels. For example, if a module has 32 pixels horizontally and 16 pixels vertically, the resolution of this module is 32×16.

Cabinet resolution

Cabinet resolution, also known as screen resolution, is the number of pixels of the entire LED cabinet composed of multiple LED display modules. For example, if a cabinet is arranged by 4×4 LED modules, and the resolution of each module is 16×8, then the resolution of the entire cabinet is (16×4)×(8×4)=64×32.

Resolution calculation formula = cabinet size ÷ dot pitch

For example, P0.625 LED display have a large cabinet size of 1200×675, and its resolution is 1200÷0.625, 675÷0.625, and the resolution is 1920×1080, So a single P0.625 LED cabinet can reach 2K, and only four cabinets arranged 2×2 can reach 4K resolution.

The higher the LED screen resolution, the more content can be displayed, the more delicate the picture, and at the same time, the more expensive it is.

Brightness

Brightness refers to the light intensity emitted by the LED display per unit area, expressed in candela/square meter (cd/m²). The brightness directly affects the visual effect of the display in different light environments. However, different scenes have different brightness requirements, and outdoor brightness is usually higher than indoor brightness.

For LED displays, the higher the brightness, the better. However, There must be an appropriate limit. For example, the maximum brightness of an outdoor LED display is 6500cd/m². If it is adjusted to 7000cd/m², it exceeds its tolerance range and may cause failure. Just like the air pressure of a tire, if the tire can only withstand 240kPa, but it is filled to 280kPa, although it will not be felt at the beginning, it may cause serious problems such as tire blowouts after a long time.

• Indoor: 600~1200cd/㎡
• Semi-outdoor: >2000cd/㎡
• Outdoor (facing south): >4000cd/㎡
• Outdoor (facing north): >8000cd/㎡

Note:

The above data is for reference only.

Advanced:Key factors affecting LED display effect

Frame rate & refresh rate

The speed at which the LED screen updates the image within a unit time (1 second) is the frame rate (Hz). Common frame rates include 30Hz, 50Hz, 60Hz, etc. The videos are composed of frames of pictures, similar to comic strips. The process of picture replacement is called frame change. For example, if the action in one second is shown through 20 pictures, the frame rate of the video is 20Hz. The higher the frame rate, the stronger the image continuity felt by the audience, and the more comfortable the viewing experience.

Frame rate is often confused with refresh rate. Although both are in Hertz (Hz), there is a significant difference. Refresh rate refers to the number of times a lamp bead on an LED screen lights up and goes out in one second. Common refresh rates are 1920Hz, 2880Hz, 3840Hz, etc. Generally, the higher the refresh rate, the better the image quality.

The refresh rate is determined by the LED driver chip, so we need to consider the selected refresh rate when choosing an LED display. lower refresh rates LED displays may have a water ripple effect when shooting with a mobile phone, while high refresh rates screens will not have this problem. In short, frame rate is mainly for video sources, while refresh rate is for displays.

Contrast Ratio

Contrast refers to the brightness ratio between the brightest and darkest parts of an LED display. A high-contrast LED display can present brighter and more vivid colors and clearer image outlines.

Technical implementation: In LED display manufacturing, contrast can usually be improved by optimizing the luminous efficiency of LED lamp beads, improving screen surface treatment technology, and enhancing the uniformity of screen backlight.

Application scenarios: High-contrast LED displays have better visual effects in video playback, picture display and other occasions; and in some scenes that need to present complex images and colors (such as art exhibitions, museum displays, etc.), high contrast is indispensable.

Viewing Angle

The viewing angle refers to the maximum angle range at which the audience can clearly see the screen content when viewing from the front of the screen. The larger the viewing angle, the better the effect when the audience views the screen from different positions. Generally speaking, the viewing angle of LED displays is between 120 and 160. With the advancement of technology, some advanced LED displays can also achieve full viewing angles.

Control method and signal interface

The control method refers to the driving method of the LED display, including synchronous control and asynchronous control. Synchronous control needs to be connected to a computer or other device to achieve real-time display; asynchronous control has independent data storage and processing capabilities and can run independently from the computer. The signal interface refers to the type of interface that connects the display to external devices, such as HDMI, VGA, DVI, etc.

How to choose the most suitable LED display

Above, we have introduced several key parameters of LED displays. When we choose an LED display, we focus on the following aspects:

Viewing distance and size

The viewing distance refers to the average distance between the audience and the display, which directly affects the choice of screen size. For example, on a large outdoor billboard, the viewing distance may reach tens of meters or even hundreds of meters, so the screen size needs to be large enough, and the pixel pitch can be appropriately increased, such as using P10, or P6, P25 outdoor LED screens.

For Indoor application, such as conference rooms or retail stores, the viewing distance is closer and the screen size can be relatively small. You need to choose a smaller pixel pitch, such as: P2 (2mm) or less.

Example: If you want to build an outdoor advertising screen with an area of ​20 square meters, the expected viewing distance is 50 meters, then it is appropriate if you choose a P10 LED display. This pixel can ensure the clarity of long-distance viewing and control costs.

Use environment and needs

Environmental brightness: Outdoor displays require higher brightness to counter direct sunlight and ensure clear visibility even under strong light. Generally speaking, the brightness of outdoor LED display screens should reach 5000-10000 nits (nit) or above.

Waterproof and dustproof level: Outdoor LED display screens usually need to have IP65 and above waterproof and dustproof levels to ensure normal operation in bad weather.

Cost and budget

Initial investment: The price of LED display screens is affected by factors such as its size, resolution, brightness, and technology. If your budget is limited, you can give priority to smaller screen size and larger resolution, and appropriately sacrifice some other features.

Running cost: 

In addition, you need to pay attention to other operating costs, including energy consumption, maintenance costs, and the cost of replacing parts. Although high-brightness LED display screens have better visual effects, they also consume more energy.

Example: A startup company, with a limited budget. They chose a medium 800cd/m2 brightness, P4 pixel pitch LED display screen for the company’s front desk display and product launch conference, which not only met the needs but also controlled the cost.

Conclusion

Through the detailed analysis of this article, we believe that you have a deeper understanding of the key parameters of LED display screens. When actually choosing LED display screens, we recommend that you make the most suitable choice based on your actual needs. At the same time, you should also pay attention to choosing some well-known manufacturers, such as Doitvision, to ensure the quality of the products and after-sales service. If you have requirement for LED display screens, please feel free to contact us.