According to some, this characteristic is the most important for LCD-TVs. Others believe that it does not reflect the real image quality. In any case, enough funds have been spent on the development of the topic to draw attention to it.
Among the factors that determine the quality of displaying "pictures" on an LCD TV screen, the "response time" specification usually receives the most ambiguous assessment from specialists and ordinary users. Unfortunately, this is not only due to the usual pluralism of opinions inherent in any field of knowledge. TV companies have done a lot to create confusion on this issue.
In general, response time is the rate at which the liquid crystal cell-pixel of an LCD screen is able to change the degree of transparency, forming an image. However, almost every manufacturer considers it his duty to introduce his own "coordinate system", based on his own ideas about the essence of the phenomenon.
The main point that unites all the disparate specifications - for all systems, it is generally accepted that the lower the response time, the higher the image quality. This is especially true for outdated LCD TVs or products from "third division" manufacturers - young Korean or Chinese companies that do not have enough funds to implement effective technologies.
Large response times mean, first of all, a blurry "picture". In this case, fast moving objects leave behind a so-called trail that is noticeable to the viewer's eyes. First of all, this property can manifest itself when watching sports programs, dynamic scenes in films, and fans of action-computer games can also experience its effect (when playing on a set-top box or connecting a TV as a monitor).
Whatever the brightness, contrast, and resolution of a TV screen, slow response times can ruin your viewing experience. Therefore, part of the manufacturers, which have small material and technical capabilities, approached the issue creatively - by inventing their own systems for measuring the response time.
Options
For early LCD TVs, there was only one measurement standard - the so-called rise-and-fall response or TrTf (Time rising, Time falling). In this case, the transition time (in milliseconds - ms) of the "liquid" crystal from the active state (black) to the inactive state (white) and back is indicated. In reality, 90% activity for black and 10% activity for white colors are taken into account. The well-known standards developer VESA has adopted it for TVs and monitors.
However, there are no hard directives here yet. Despite the authority of VESA, manufacturers have found room for manipulation within this framework. So, for example, in the specifications of the TV set, only half time is indicated - the transition of the cell from black to white. This allows you to "cut" the response time in half. An additional possibility of manipulating numbers is the declaration of the maximum pixel response speeds instead of the average ones.
Another way to measure response time is GTG (Gray to Gray). What is measured here is not the transition from black to white, but the gradation time from one gray tone to another. It is clear that all these specifications do not correlate with each other.
Noting the response time indicator in the instructions, not all manufacturers indicate by which system they are measured. Many do not indicate it at all. Some - because they do not consider it important, others because there is nothing to indicate to them, in fact.
"Canonical" variant
And, nevertheless, the most common standard is TrTf (Time rising, Time falling). First of all, it is used by large companies "with a name".
The optimal response time for this system in the recent past was 20-25 ms. According to experts, this is quite enough for comfortable viewing of "fast" video. However, if you believe the users, some of them are able to distinguish the loop and twelve, and even eight milliseconds. Obviously, these are individual features of the visual perception of individuals, because, according to some estimates, the image on the screen of a 50 Hz CRT TV is approximately equivalent to 16 milliseconds of LCD.
Conclusion
Under the circumstances, it is impossible not to admit that although "response time" is certainly an important value, the main attention should be paid first of all to the details: the measurement system, the subjective rating of the manufacturer, etc.
Fortunately, VESA has already begun to unify a common standard based on TrTf. It remains to be hoped that soon it will be adopted everywhere.
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April 26, 2024 13:01:48 +0300 GMT
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