There are several parameters for a monitor to be qualified as best or at least optimum. The most common and important ones to look at are the refresh rate, viewing angle, color reproduction, and response time.
The manufacturers advertise the monitors based on these characteristics. But we have become clever enough to realize that not all advertised features are necessary.
You may have guessed that the refresh rate, viewing angle, and color reproduction are quite important, even from their names. But what exactly is a monitor’s response time, and does it really matter? Let’s find out.
What is Response Time?
A computer receives many images and videos as input. The color range of these visuals varies a lot: some can be completely white, some totally black, and some colorful, like a rainbow.
Most of the monitors consist of LED illumination and color filters (Red, Green, Blue) to generate these colors. So, when there is a need for a darker portion in an image, the light is blocked, and for a bright portion, the light from these LEDs is allowed to pass.
However, it takes a while for the darker image to turn white. This time required for the pixel to shift from black to white, and then black again, is the response time of the monitor. It is known as B-to-B response time.
But the B-to-B response time is quite high as the LED needs to completely shut off, illuminate again and then close again. Thus, nowadays, the response time is usually measured instead in the Grey-to-Grey shift.
Here, the backlight is not shut off totally, and the time measurement is done for the shift from one grey level to the next grey level. For instance, the 4 ms GtG response time of a monitor panel means that the monitor takes 4 milliseconds to change its greyscale color levels.
The greyscale consists of a mixture of both black and white, and different combinations of it, along with a color filter, can represent most colors in images. So, GtG response time is taken as the accurate measurement for the monitor’s response time.
Does the Response Time Affect Our Viewing Experience?
So now, do you think a slight delay in the color shift will impact your work? It depends.
Most Monitors have a response time below 10 ms. So, if you use your system for basic browsing, office work, or any simple tasks, then this lag won’t even be noticeable. Even while watching some movies, response time will play no major role in changing your experience.
However, the difference comes in gaming and movies with fast motions. Whenever the monitor’s response time is high, the rapidly changing images and scenes in games and movies can leave a trail behind. You will see the earlier image lingering over the new scene as the monitor is still shifting the colours for the former when the later scene pops up.
This phenomenon is called ghosting, and response time is majorly responsible for it. Apart from this, you will experience motion blur in fast-paced scenes. But these issues are not the case of response time alone.
You will also have to take the refresh rate of the monitor into account. This is because you will experience ghosting only if the monitor refreshes the screen faster than its response time.
Let’s look at this clearly. Suppose you have a monitor with a refresh rate of 60 Hz. It means that it can show 60 frames in 1 second on the screen. As 1 second is 1000 milliseconds, it will require 16.67 ms to load one frame. Now, even if your monitor has a response time of 10 ms, then the colour shift will happen before another frame is loaded on the screen.
However, for a monitor with a 144 Hz refresh rate, it will take around 6.94 ms to load one frame. So, the response time will have to be lower than 5 ms to not experience ghosting.
Similar is the case for the video or games’ frame rate. If the game displays higher frames per second (fps), then you will need a monitor with a lower response time for better performance.
So, all in all, response time matters in cases of high fps games and higher color variation scenes, such as in movies. And it can ruin your experience a bit if you have a monitor with a higher refresh rate.
Having said that, nowadays, with the progress in nano IPS panels, OLED displays, and overdrive settings in monitors, the response time has lowered a lot, even before 1 ms. Most monitors have started to provide a response time of 5 ms or lower. So, such a lower response time can cope with the currently available refresh rate and frame rate of monitors. And you may not have to worry alot about the response time.
Is It the Same as Input Lag and Latency?
Sometimes, while looking at the features of the monitors, people may use the term “response time” or “response rate” for input lag and latency. This can create confusion among people on whether the feature is essential or not.
Input lag means the time taken for the result to appear once you have given the instruction. For instance, you inserted a USB drive into the monitor and loaded an image from it. The time taken from the instant you double-clicked on the image file to when the image is seen on display is the input lag.
Input lag consists of both the lag due to the monitor’s circuitry and the pixel response time. Similarly, Latency means the lag in the processing of the signal by both system and the monitor but not of the colors.
However, the response time is the monitor’s time required to shift between colors in comparison to the lag by efficiency and circuitry of the whole system, as in the case of input lag and latency.
Nevertheless, if there is already latency in the monitor, then it impacts the response time automatically. This is because you will not see the color shift until the image is processed first due to the latency.