You probably already noticed that at the beginning of the year there was a lot of news that a new gadget was released or will be released, the frame rate of the screen of which will be higher than now. First of all, this applies to smartphones and gaming monitors. The only question is whether such a frame rate is needed. For example, if a smartphone starts displaying a picture with a frequency of 120 Hz, is that so good? On the one hand, yes, but this phenomenon also has disadvantages. At the same time, they sneak up, as they say, from where they did not expect. Are you sure you want further frame rate increases?
We have already increased the number of screen tones, it remains to increase the refresh rate.
I will not burden you with complex terms and talk about where the concept of “sweep” came from and how cathode-ray tubes worked, from which everything went. Better just speculate on a topic that is so urgent now.
First of all, we must understand that we are promised screens with a frequency of, for example, 120 Hz. If you write on the box with a smartphone that it has such a frequency, most likely, you will want to buy it, because “the frequency is high, everything is cool, you have to take it”. In fact, not everything is so smooth. Sometimes it happens that this figure does not hide the actual frequency of redrawing images on the screen, but the reading frequency of the screen sensor.
That is, 120 Hz in relation to the image itself indicates that the picture will change 120 times in one second. This is a lot and the picture will move very smoothly, because even 60 frames per second looks much better than 30. For example, just try to shoot a video at 60 frames per second and watch it on your smartphone screen. If your device has a good screen, you will immediately understand the difference and don't want to shoot at 30 fps anymore.
One of the first devices with a 120 Hz screen was at one time iPad Pro, which performed well and the image on its screen moved very smoothly. At the same time, iPhone XS and other models of this series also promised a 120Hz screen, but in this case it was just about reading touches. That is, in one second, the sensor receives information about the position of the finger 120 times. With some simple calculations, we get one read in 8.3 ms versus 16.6 in the case of 60 Hz. Improving this metric is also good, but it is not that important and will hardly improve the perception of a smartphone.
Released last year, the OnePlus 7 Pro with a 90Hz refresh rate does indeed hit 90fps. First of all, it is felt well when scrolling through the interface. The absence of even a slight blur and smoother movement of icons and menu items creates a subjective feeling that the smartphone is working very quickly.
The refresh rate of this OnePlus' screen makes it feel like it's running faster than it actually is.
All this has to do with perception. In general, it is believed that our brain ceases to perceive the video sequence as a change of pictures after a frequency of 15 frames per second. It is after this value that we see the video. Freezing, twitching, blurry, but video. That is, we get the illusion of movement. By the way, this is exactly the frame rate that the GoPro Hero 3 camera had in 4K mode. It didn't work out faster then.
The gold standard for cinematography is 24 frames per second. This has its own charm, as the picture is a little blurry and very cinematic. We can dive into it and go into the world created on the screen, and not perceive it as an extension of reality.
24 frames have long been the gold standard of cinematography.
Sometimes filmmakers start experimenting with frame rates, but they get their bucket of excrement on their heads and stop experimenting with the format. One relatively recent example is the film The Hobbit: An Unexpected Journey directed by Peter Jackson. In it, the creators tried to offer a 48 frames per second format, but in return they received a decent portion of criticism.
As a result, we can conclude that each “action” has its own format. For example, for shooting nature, a high frame rate is perfect. The same can be said about the shooting of a personal archive – the picture will literally be alive. But the transfer of an artistic idea does not require increased realism and it is better to dwell on small values. Gamers will object to me and they will be right. For them, it is better to have a higher frame rate, since this is what allows you to more fully immerse yourself in the gameplay, not to miss important details, and at the same time take the strain off your eyes.
There is one more thing to consider when creating and using screens with a high refresh rate. Every frame and every pixel in it is rendered by a processor with a graphics core. This means that increasing the frequency will make them work with more load. In stationary conditions this is not so critical, but in mobile devices it can have a very negative effect on autonomy.
At the same time, a high refresh rate is not always needed. When watching something static, for example, when reading a text, watching a program where only the mimicry of the host changes, in a logic game and many other places, a high refresh rate is simply not needed. There must be a balance.
Summing up the above, I want to note that I am in favor of increasing the frame rate of gadgets, although I'm not sure that I can say this about cinema. At least I've been shooting my videos at 60 fps (in Full HD) for a long time. I will be only glad if the devices can reproduce higher frame rates, but do not forget that such content takes up a lot of space. I don't want to just increase the frequency, keeping the volume and, as a result, losing in bitrate. So, we need to come up with something. Well, it would not hurt to better use the system of adaptive adjustment of the screen refresh rate.
Together, this will really bring the screens of modern devices to a new level. Otherwise, we'll get something like the ability to shoot 4K 60 fps video in a smartphone. Function for the sake of function, which is used by just a few. But everyone understands that you have a cool smartphone.