Pixel response time, and how to change it

For most TVs, motion blur is a problem in watching sports and video games because of the fast movement of the plot and the long pixel response time. In films, it is almost impossible to see the blurriness of the image due to the low frame rate of the video obtained by the slow shutter speed of the camera when creating the video. The degree of blurring that a person considers acceptable. subjective, some people are much more sensitive to this visual disturbance.

Game Monitor Features

LCD TVs and LED backlit monitors, by their nature, have a relatively long pixel response time, and OLED panels are much shorter. Video with a higher frame rate will have less blur than an identical video with less if the TV refresh rate matches that frame rate. For example, a video of 120 Hz on a TV with a frequency of 120 Hz, and not with 60 Hz.

Similarly, a monitor with 120 Hz will only have 60 Hz blur if the frame rate of the video does not exceed 60 Hz. Thus. for video from 60 Hz to a 120 Hz TV, the video signal will still be only 60 frames per second, and the frame time will not change. The same applies to 24 Hz and 30 Hz on TVs with a higher maximum frame rate.

Component Evaluation:

1. Pixel response time is the time it takes an LCD panel to go from one color to another. With a long gap, the pixels do not keep up with moving objects, and therefore you can see a long trace of blur following them.
2. Most motion controls are static.

Causes of Motion Blur

One of the effects of a slow refresh rate or pixel response time is that the image may look blurry. This happens for several reasons.

The first is related to response time. If you are slow, it takes some time to completely switch from your previous state to a new one. This leads to the fact that behind the new will be a hidden or ghostly image. The slower the response of pixels, the longer the track and the less clear the picture. The parameter, what is the best response time of a pixel on a TV, depends on the technical characteristics of the model.

The second reason is eye tracking. The brain may perceive the image as blurry. Eyes, of course, track the image on the screen, but since it is static, even for a split second, the eyes sense perception when the gaze slides across the screen.

Motion blur is created by several parameters:

1. Response time - the parameter shows how long the pixels of the TV go into a new state. A longer time means longer blurry tracks on moving objects. Gamers first want to know which pixel response time is better on a TV when switching from one color to another.
2. Frame time - the amount of time the frame is displayed on the screen. The longer the frame time, the more blur is fixed.
3. Blur inside the video itself. This is due to the action of the camera exceeding the shutter speed. Filmmakers usually consider it this kind of blur when planning for a movie or show.
4. Any delay may occur due to the use of a wireless keyboard, mouse, and the Internet.

If the display primarily watches video, audio, or games, which requires an exact pixel response time (ms), consider testing the settings for input delay.

Response options

This time required for a pixel to switch from one color to another is measured in milliseconds (ms) and is directly related to the refresh rate. Because the monitor quickly updates the image, what is the best response time for a pixel will depend on how quickly the pixels in the monitor respond. A response time of 16 ms corresponds to a theoretical maximum refresh rate of 60 Hz.

Response time is defined as the time it takes a pixel to go from black to white and vice versa. Most manufacturers display gray-to-gray or GTG response times to post messages faster.

The response time of a matrix pixel is usually presented in milliseconds. A longer response time can adversely affect gameplay or movie watching, leaving traces called ghosts. This failure is not only confusing, but also distracting from sensitive games.

Input latency is the time difference compared to when a user types a command from a keyboard, mouse, or other peripheral device, and when it appears on the display. This can greatly affect performance in FPS, RTS, and fighting style games.

TN or twisted nematic panels typically have shorter response times. However, many IPS panels, especially those used with market-based gaming monitors, have low enough response times to avoid even the smallest split.

Related TV settings

Motion interpolation increases the frame rate of a video by creating and inserting transition frames between existing frames of the original, reducing the response time of the monitor pixel, frame time, and creating a smoother overall look. Moreover, since it does not improve, the length of the track on moving objects does not change.

Some televisions have the ability to add flickering backlight or insert black frames to reduce frame time and clarify movement. It also has the effect of dimming the maximum brightness, although, as with interpolation, this does not affect the response time. In this case, the length of the track on moving objects does not change, and the refresh rate does not affect it either.

It is not possible to compare the response times indicated by different manufacturers and reviewers without knowing the testing methodology. Experts tested several transitions from gray to gray and presented an average value, but some brands indicate the shortest response time that the screen is capable of or test the time required to switch from one shade to another and then back.

Monitor refresh rate

For many years, the refresh rate and the choice of the pixel response parameter has been a popular study for gamers when buying a monitor. Since these characteristics show the rate of change of the image and characterize the number of updates per second, the value of which contributes to a better perception. To compare what pixel response time is better on the monitor, it is measured in hertz (Hz).

The standard baseline for this indicator, which provides a satisfactory image, depends on the particular application of the panel. Home theaters are able to provide high-quality display from 24 Hz, and the old TV standards PAL and NTSC from 50 Hz and 60 Hz, respectively. A typical PC monitor has 60 Hz, but the latest gaming monitors reach 240 Hz.

For a long time, 144 Hz was actually the standard refresh rate of the gaming monitor (6x24 Hz), but now there are enough panels on sale with a frequency of 240 Hz.

You need to be frank. If the user does not actually play competitive multiplayer games, especially FPS, then it is better to give preference to image quality rather than refresh rate and response time. That is why models such as the Asus PG279Q and Acer XF270HU proved to be so popular and find the perfect compromise between all the important factors.

Parameter adjustment

It is generally believed that a pixel response time of 5 ms or less is good for games. Most monitors, even IPS panels, which are listed as gaming monitors, are usually very good in this area. Checking customer reviews for problems with side effects is a good way to determine if the manufacturer has not indicated a real response time.

There are several steps that you can take to reduce the input delay, monitor if it has no restrictions. Therefore, it is important to choose the right monitor or TV from the very beginning.

A 8 ms pixel response time is acceptable for games. In general, input lag is longer on TVs where additional processing is performed.

Some simple ways to troubleshoot a visual glitch and reduce input latency include the following:

1. Change display mode.
2. Change console settings.
3. Change cord from HDMI to VGA.
4. Use lower resolution.

The base frequency is usually from 30 Hz to 60 Hz, which means that such a pixel response time on the TV will not be small. LG Smart TV with the features of TruMotion technology, which allows to increase hertz by interpolation, that is, creating intermediate frames of the hybrid between the images, providing a clearer picture of movement and reducing flicker. Thanks to this technology, you can increase the refresh rate to 120, 240, and even up to 480 Hz.

For LG TVs, follow the instructions to access TruMotion options:

1. Go to "Advanced Settings".
2. Select “Image”, then “Settings” and finally “Options”.
3. Choose TruMotion.
4. Try the setting options or disable the function.

Elimination of lag delay

Input latency typically occurs in flat-panel LCDs and plasma displays because the screen takes time to process the image in order to improve its quality. If you use a display or HDTV to do work, browse the web or movies, the delay is rarely noticeable.

There are several ways to measure input latency. One approach is to split the signal between the CRT display without delay and the LCD. Alternatively, they use the Human Benchmark web reaction test, which checks the response to a color change.

Gamers notice a delay in the input on the display longer than usual. The delay between pressing a button and the corresponding effect on the screen makes it difficult to perform complex maneuvers or combinations. This greatly affects first-person shooters, fighting games and rhythm games such as Rock Band and Guitar Hero.

Steps can be taken to reduce the backlog. Since all flat panel displays have some delay, they lower it to the point where the gamer will stop noticing it.

First, check if the TV has a game mode. This is basically a display mode that disables post-processing due to a slight decrease in image quality. Then disconnect as many other video processing parameters as possible. Each manufacturer has a tendency to identify its features with different acronyms, such as DRE or 3DNR, to achieve quality, you need to try to turn them off and see if the backlog improves.

If you use HDMI or component cables to connect the settings to the display, try using VGA and HDfury instead.

Game Mode Setting

If the TV has a game mode and it is not used, then there will be a delay in input. This is due to the fact that, as a rule, newer televisions perform their own image processing before displaying it on the TV, which leads to a delay between the output of the source and the displayed results. Setting the TV and monitor in game mode will eliminate this processing and provide a 1: 1 source for displaying bandwidth.

You can use the Leo Bodnar input delay tester to optimize your TV settings:

1. Switch input mode from AV to PC / HDMI.
2. For monitors and TVs that have an HDMI mark instead of “PC”, for example, for 90% of Samsung and LG products, you must manually rename the input mode to “PC”.
3. Turn on game mode, if available. If the user is fond of calibrating television images and is disappointed with the lack of fine-tuning the white balance, check if there is a factory menu for more detailed settings.
4. Game mode is the most important thing you can do, as it reduces input lag and is found on most modern TVs, where settings, including colors, blur and other variables, are set specifically for video games, and help reduce video game lag. While certain settings may help with moving graphics, such as live sports broadcasts, these same settings may lead to a delay in the video game or a feeling of delay. In most cases, this option disappears after selecting PC mode. It usually stops everything in post-processing, which causes a delay in input, while game mode usually stops only for HDMI mode.
5. Find a setting called “Response Time” or “Pixel Overload”, “Overload”, usually something like “Normal”, “Faster” or “Fastest”.
6. Turns off any power-saving settings or dimming the surrounding screen. Both of them add extra lag (~ 10 ms each).
7. Check each HDMI input. It happens that out of 4 HDMI inputs, two or more have a lower input delay (6 ms less) than the others.
8. Using the TV speakers, add input delay. If possible, use a separate audio system, such as a soundbar. Often this tool can add ~ 8 ms of delay.
9. Some televisions, such as Vizio, have the effect of smooth movement - turn it off.

MPRT Tests

For a serious test of the display, you can use the PixPerAn (Pixel Persistence Analyzer) test, which helps to perform pixel sensitivity analysis. It uses the principle of traditional static photos or videos. You can use this test to calculate values ​​known as MPRT (Moving Image Response Time).

MPRT is the general level of perception of the movement of thoughts on monitors. The test allows you to use a range of pixel transitions, ranging from black (gray 0%) to white (gray 100%) with intermediate gray steps of 25%, 50% and 75%. MPRT is designed to reflect the “overall visual review”, so the frequency of updates and the behavior of the monitor are indeed the main factors.

Especially slow pixel responses can slightly increase MPRT values ​​to get a representative result. This is because transitions to artifacts can be very important when using aggressive acceleration of gray to gray. Such artifacts, of course, can have a significant impact on MPRT and therefore should be used separately.

Using PWM

Pulse Width Modulation (PWM) is a method used to modulate the brightness of the backlight on some samples and images on the LCD. In order to use alternating current to modulate the brightness, the PWM-controlled light source quickly turns on and off to achieve a given brightness. Some people are sensitive to visual discomfort. Flickering also has effects in order to perceive objects on monitors. This may be a visible fragment of blur that is felt when viewing moving images. Fragmented blurring is called a PWM artifact.

LightBoost and stroboscopic illumination include on and off pulses, which allow displaying information on the LCD screen only for those users who share seconds and do not display anything for the remaining time. This is only due to the fact that the driving force of the pulse, including overload artifacts, which can cause aggressive acceleration of gray to gray. Sony Motionflow is one of the most popular systems available for LCD TVs.

The basic Motionflow includes the use of MCFI technology (Motion-Compensated Frame Interpolation), through which intermediate frames are created and inserted between real frames to increase the refresh rate.

We can summarize: it is obvious that the best choice for buying a TV with a little blur is to find a model with a low response time. The user can reduce the degree of blur by watching videos with a higher frame rate by turning on the motion interpolation or backlight flicker functions, bringing the pixel response time to 1 ms. It should be remembered that the inclusion of these additional functions can lead to other problems in the video, so everything needs a measure.