6 Tips for Calibrating Your LED Display Screen

12/31/2024
07:21

By adjusting brightness, contrast, white balance, color accuracy, pixel uniformity, and testing for motion artifacts, you will considerably enhance display quality for clear and realistic advertisement content, offering a better viewer experience.

Set Brightness and Contrast

In bright environments, the brightness needs to be increased by 20% to 30%. For example, in environments with 500 to 1000 lux, set the display brightness to 350 to 400 nits to ensure clear visibility. In low-light environments, the brightness should be set to 100 to 150 nits to reduce eye strain while maintaining display quality.

A too-high contrast ratio like, for example, above 5000:1—causes loss of detail, whereas too low a contrast ratio leads to a flat image. Normally, the contrast ratio should be within the range of 1000:1 and 3000:1; in HDR content, displays can go up to 4000:1 or more for better display of detail.

This is important because standardized test images help evaluate the adjustment effect and balance between brightness and contrast. In many cases, by default, displays do not achieve optimal performance; for example, some displays are set to 250 nits by default while the ideal should be 300 to 350 nits, requiring fine-tuning with professional tools.

If the screen allows it, automatic brightness adjustment is better to be turned off. Too much brightness not only wastes power but also decreases the lifespan of the LED screen. Most LED screens today are rated between 30,000 and 50,000 hours.

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Adjust White Balance

White balance is measured by color temperature (Kelvin, K). The standard white light color temperature is around 6500K, which is close to natural daylight. If the color temperature is too high, the image may show a bluish cold tone; if too low, the screen will show a yellowish warm tone.

With white set at 6500K—that’s the default for most displays—you’ll want to adjust the color temperature. Note that a professional colorimeter will give you more accurate color temperature readings; these are helpful if you want to perform accurate screen calibration.

Most high-end displays can support adjusting RGB gain or offset. Fine-tuning the gain of the red, green, and blue channels helps to make the white display more neutral, preventing it from excessive color shifts. For example:

Gain increase of blue decreases warm tones for a cooler white shade.
Gain increase of red makes white lean towards a warmer tone.

Using standard white or gray uniform images can help in detecting any color temperature deviation. In case some color differences in white or gray areas start to become noticeable on screen, micro-adjustments will be necessary.

If you’re interested in customizing LED displays, check out the 6 key factors here.

Calibrate Color Accuracy

You need to opt for professional color calibration software, like X-Rite i1Profiler or Datacolor Spyder, which can auto-detect and adjust the RGB channels for color reproduction. About 90% of displays are not well color-calibrated out of the box, while with the help of the right software, it will get more than 95% color accuracy.

Using a hardware colorimeter-a device that measures color, such as the X-Rite i1Display Pro or the Datacolor SpyderX-can directly measure the screen for its color output for color accuracy. Place a colorimeter on the screen, and the device reads light data, after which software adjusts the settings of a display based on this information.

Setting the standard color temperature will be important for the most accurate white display, which is usually set to 6500K. At 6500K, it closely approximates daylight standards, which can prevent color shifts. In that vein, choosing the appropriate color gamut–sRGB, which covers about 100% of the standard color gamut, or Adobe RGB, which covers 75% of the NTSC color gamut-especially for graphic design or video editing, is highly important.

The adjustment will also optimize the RGB channel gains and offsets using calibration software to make accurate white and smooth color transitions. Check the display performance for color using grayscale or color bar test images after calibration.

As the display color will drift over time, recalibrations every 1 to 2 months will keep colors as close to accurate as possible. Most high-end displays can hardware-calibrate, and when that is not an option, third-party tools will give more precise color adjustments.

Check out the difference between indoor and outdoor displays here.

Check Pixel Uniformity

The easiest way is to display a single color, like white, gray, or black, in full screen and check whether there is brightness or color deviation. According to data, about 30% of LED displays have pixel uniformity issues when displaying a single color, especially in the four corners and edge areas of the screen. For lower-end displays, about 20% of products show noticeable color deviations when displaying gray or white.

If any possible issues are noted, try adjusting the brightness and contrast first. This often greatly improves pixel uniformity. Sometimes, when contrast is high or brightness settings are low, this is beneficial.

If the problem remains after adjustments, use a colorimeter—such as X-Rite i1Display Pro or Datacolor SpyderX—to measure the brightness and color output of the display with precision. Research has shown that a colorimeter can enhance display accuracy by 30%, which helps to eliminate subtle differences in brightness and color deviations.

Since the non-uniformity of pixels is often focused on the corners and edges, these areas should be given special attention during inspection. If the problem is more serious and cannot be solved through software adjustments, please contact the manufacturer for repairs, especially if the issue comes from the backlight design or manufacturing process.

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Test for Motion Artifacts

Testing for motion artifacts is one of the key quality checks in advertising LED displays, especially in showing dynamic ads. These normally appear as blurring, trailing, or ghosting of images and thus give a poor impression to the viewer, and maybe information is not delivered effectively.

How to detect motion artifacts:

Play dynamic content: Play high-action or fast-changing images and videos—for example, fast-moving objects or high-contrast graphics. These contents quickly reveal motion artifact issues.
Observe screen response: Observe the screen carefully for trailing, blurring, and ghosting, especially where there is fast motion; if the image blurs or its clarity diminishes, then there might be the presence of motion artifacts.
Refresh rate and response time: If these artifacts are observed, the motion may be due to either refresh rate or a response time. Test adjustments in display settings. Compare with other displays as a means of identifying artifact source.

How to reduce motion artifacts:

Increase the refresh rate: The refreshing rate is one of the most effective ways to handle artifacts. Many high-end LED displays for advertising are already capable of providing a refresh rate of 120Hz or higher. Based on the studies, the high refresh rate reduces about 50% of the motion artifacts, which is a great benefit to dynamic display.
Shorten the response time: When the response time is long, fast-moving images tend to trail. In order to shorten this, the response time of the advertising LED display shall be less than 5 milliseconds.
Use motion compensation technology: When there are still some remaining motion artifacts after improving refresh rate and response time, this can be further improved through the use of motion compensation technology. It works through the insertion of additional frames, reducing discontinuities and ghosting of moving images.