If you've landed on this article, you're probably trying to understand what refresh rate is, and why it matters so much on an LED wall. Have you ever tried filming an LED screen with a smartphone, only to end up with those annoying black lines running across the video?
Lately, customers ask us about LED screen refresh rate more and more often, mostly because they're working with filming, virtual production, XR photography, and similar applications. That's when the real question comes up: what's the actual difference between a high refresh rate and a low one?
Refresh Rate vs. Frame Rate
Refresh rate is easily confused with video frame rate (FPS, frames per second). The two concepts are closely related: both describe how many times a static image is displayed per second. The difference is that refresh rate refers to the video signal or the display itself, while frame rate refers to the content being played.
The refresh rate of an LED screen, not just an LED wall, is the number of times per second the display hardware refreshes its data. This is distinct from frame rate: an LED screen's refresh rate includes redrawing identical frames repeatedly, while frame rate measures how often a video source can deliver an entirely new frame of data to a display.
Video frame rate is typically 24, 25, or 30 frames per second, and anything above 24fps is generally perceived as smooth by the human eye. With recent technological advances, audiences can now watch 120fps video in cinemas, on computers, and even on mobile phones, which has pushed higher frame rates into more widespread use for video production.
So What Does Refresh Rate Actually Mean?
Refresh rate can be split into vertical and horizontal refresh rate. Screen refresh rate generally refers to the vertical refresh rate, meaning how many times the electronic beam scans and redraws the image on the LED screen.
In practical terms, it's how many times per second the LED screen redraws the image. Screen refresh rate is measured in Hertz (Hz). A refresh rate of 1920Hz, for example, means the image is redrawn 1,920 times per second.
High vs. Low Refresh Rate
The more often a screen refreshes, the smoother the motion rendering and the lower the flicker. What you see on an LED wall is technically a sequence of static images; the perceived motion comes from the display constantly refreshing, creating the illusion of natural movement.
Because the human eye briefly retains a visual impression, one image blends into the next before the previous impression fades. Since consecutive images are only slightly different from one another, static frames link together into smooth, natural-looking motion, as long as the screen refreshes fast enough.
A higher screen refresh rate ensures high-quality images and smooth video playback, helping communicate messages and products clearly to your audience. A low refresh rate, on the other hand, makes the LED display's image transmission look unnatural. It also causes flickering black scan lines, torn or streaked images, and moiré or ghosting effects in mismatched colors. Beyond the impact on video and photography, tens of thousands of LEDs flashing simultaneously can cause visual discomfort for viewers, and in some cases, eye strain.
A low refresh rate on an LED wall tends to leave viewers visually fatigued, and can leave a poor impression of your company or brand image.
What Refresh Rate Does an LED Wall Need?
A higher refresh rate reflects the display hardware's ability to redraw screen content more times per second. This produces smoother, cleaner motion, particularly in dark scenes with fast movement. A display with a higher refresh rate is also better suited to content shot at higher frame rates.
Generally, a refresh rate of 1920Hz is sufficient for most LED displays. If the display needs to show high-speed action content, or will be filmed by a camera, a refresh rate above 2550Hz is required.
Refresh rate depends largely on the driver chip used. With a common driver chip, the refresh rate for full color is typically 960Hz, and 480Hz for single or dual color. With a dual-block driver chip, refresh rate exceeds 1920Hz. With a high-end HD PWM driver chip, refresh rate can reach 3840Hz or higher.
High-quality HD PWM driver chips, with a refresh rate of 3840Hz or above, deliver a stable, smooth screen display, with no rippling, no lag, and no visible flicker, while also reducing eye strain for viewers.
In professional use, a very high refresh rate is essential, particularly for entertainment, media, sports broadcasts, and virtual production scenarios that will certainly be captured on video by professional cameras. A refresh rate synchronized with the camera's recording frequency produces a clean image and prevents flicker. Cameras typically record at 24, 25, 30, or 60fps, and refresh rate needs to stay synchronized with that frame rate as a multiple. When the camera's capture timing aligns with the screen's image change timing, the black scan line issue during screen refresh can be avoided.
3840Hz vs. 1920Hz Refresh Rate
At 1920Hz, the human eye generally can't detect flicker, and this is sufficient for advertising and general video viewing.
At 3840Hz or higher, a camera can capture the screen with a stable image, effectively resolving trailing and blurring issues linked to fast motion, while improving image clarity and contrast, so the resulting video looks smooth and doesn't strain the eyes.
How to Increase Refresh Rate
- Better hardware, a high-end driver IC, and good PCB design all help increase refresh rate.
- Changing the scanning pattern, using more driver ICs, and increasing buffer data processing capacity.
- Using reliable control software, such as Novastar, which significantly improves refresh performance.
One thing worth keeping in mind: unlike grayscale, pushing refresh rate too high carries some risk. As refresh rate increases, the demands on LED quality increase with it. If LED quality isn't high enough, the components won't withstand the stress of a high refresh rate and will fail more easily. As a rule, refresh rate should stay below the manufacturer's maximum rated value, for example 3840Hz; pushing beyond that threshold will shorten LED lifespan.
In Summary
If you're using an LED wall for commercial or professional purposes, video presentations, broadcasting, or virtual production, it's always best to choose an LED screen with a high refresh rate that syncs with the camera's recording frame rate. This is how you get a clean, high-quality image, the same standard delivered by the Atomic Pro Prime Series 3.9 MK2.
