What is LED Screen Refresh Rate?
Refresh rate is an important indicator used to characterize the non-flickering and screen stability of an LED display. It mainly refers to the update rate, which becomes almost indistinguishable to the ordinary human eye when it exceeds 60Hz. A higher refresh rate results in lower picture flicker and a sharper image. Conversely, the lower the refresh rate, the more likely it is that the picture will flicker
The refresh rate indicates how many images per second are displayed on the LED screen. Thus, the faster it is, the more precise the image becomes, and a faster refresh rate also corresponds to a higher number or level. Generally, a better refresh rate is associated with a higher number, for example, 1920Hz rather than 720Hz. Therefore, the refresh rate is an important indicator of the visual stability of LED screens.
The Difference between Refresh Rate and Frame Rate
Another concept that is often confused with the refresh rate of LED screens is frame change frequency. Frame change frequency refers to the attribute of video pieces, indicating the number of times the picture information is updated per second. Therefore, frame change frequency is an important indicator for measuring video continuity. If the frequency of frame changes is low, flickering may occur. Furthermore, if the refresh frequency value reaches a point where ‘picture flicker’ is noticeable, the frame change frequency will influence this flickering effect.
Frame rate indicates the detail of an image, while refresh rate defines the smoothness of an image on the LED screen. Frame rate refers to the number of individual frames displayed per second in the source content and is measured in frames per second (fps). Both refresh rate and frame rate affect visual quality. However, refresh rate is a parameter of the LED display device, and frame rate is an attribute of the video file. Achieving a harmonious balance between the two is essential for optimal visual quality.
The Difference between a High Refresh Rate and a Low Refresh Rate
Higher refresh rates are better for three primary reasons: input latency, smoothness, and visual clarity. Smoothness increases at higher refresh rates because more frames are being shown. This would be quite clear if we observed 30fps and 60fps footage side by side. When more frames are displayed and the differences between each frame in motion are smaller, the smoother the gameplay becomes. Some game developers attempt to hide this through the use of motion blur, which blurs frames together to reduce the apparent differences between each frame at low frame rates. However, when motion blur is disabled, the differences in smoothness between low and high refresh rates become very obvious. These smoothness benefits extend to refresh rates above 60Hz. For instance, 120Hz is noticeably smoother than 60Hz, and 240Hz is even smoother. Again, however, how noticeable these jumps in smoothness are depends on the viewer’s sensitivity.
Input latency decreases at higher refresh rates due to the reduced time between updates. For example, at 60Hz, the display is fully updated every 16.7 milliseconds, while at 120Hz, it updates every 8.3 milliseconds. The benefits of higher refresh rates for visual clarity are due to the way modern display screens, both LCD and LED, typically operate. They are sample-and-hold displays, meaning each frame is shown on the screen for the full duration of each refresh cycle, without gaps or black periods between frames. Sample-and-hold displays can appear blurry when your eyes track a moving object across the screen, such as an enemy in a gunfight or an interesting feature in the environment while walking. This blur occurs because your eyes move at a constant, steady rate to track objects, while the actual object on the screen only updates its position with each refresh.
Between each refresh, your eyes are moving, while the object on the screen remains stationary due to the sample-and-hold display. When your eyes move but the object on the screen does not, this creates a blur, similar to how a moving camera capturing a still object can create a blurry photo. In other words, the longer the object on the screen stays in the same position without being updated, the lower the refresh rate, and the greater the amount of blur. More frequent updates with small changes between each update reduce blur on this type of display, which is why high refresh rates produce less blur. We can measure this using the Blur Busters UFO test.
1920Hz vs 3840Hz LED screen refresh rate
With the advancement of LED display technology, the LED screen industry has progressed from the original 480 Hz to 1920 Hz, 3840 Hz, and even 7680 Hz. Under normal circumstances, the human eye cannot discern these frequencies with the naked eye, as it typically cannot perceive frequencies greater than 24Hz.
At present, all modern indoor and outdoor screens can reach a refresh rate of 3840 Hz. The frame rate of a film is generally 24Hz, meaning 24 frames are drawn per second. If we play a movie with a frame rate of 24Hz on an LED screen with a refresh rate of 3840Hz, this equates to 3840 divided by 24, which equals 160. This means each frame of the movie is refreshed 160 times by the display screen. At such a high refresh rate, the human eyes do not perceive flickering in the image, because the display’s fluency and clarity are so high.
Hence, by analogy, a 3840 Hz refresh rate means each frame is refreshed 160 times on LED display screens, 1920 Hz results in 80 refreshes per frame, and 7680 Hz leads to 320 refreshes per frame. These high refresh rates can effectively reduce water ripple effects, suggesting that whether it’s mobile phone or camera footage, both can appear as authentic as possible, closely resembling what is seen by the naked eye
At present, in the LED display screen industry, there are two main display refresh rates: 1920Hz and 3840Hz. However, the older displays with a 960Hz refresh rate have gradually faded out due to screen shaking and flickering, resulting in poor display quality.
In conclusion, when choosing an LED screen, if one is unsure how to select the refresh rate, within a given budget range, 3840 Hz is preferred for both indoor and outdoor LED display scenarios. However, this choice is further subject to the limitations of the user’s needs. So, whether the requirement is for professional work or for applications such as outdoor rental for branding, video presentations, virtual filming, broadcasting, or even home gaming, a good rule of thumb is to choose an LED display screen that offers a higher refresh rate, like 3840 Hz or higher.