Modern TVs reproduce a high-quality and effective image, but for all LCD structures, work is inherent in the type of layering. Two polarizers are installed in parallel, the upper region polarizes the light without processing, and then a monoplane polarized signal is generated. The action of the lower one allows you to block the radiation of the surface layer, so the flow is rotated by 90 degrees.
This function is real due to the filling of the interlayer between the polarizers with liquid crystals. LED, OLED, QLED technologies can be used, but the outer part is always covered with a glass panel with transparent electrodes. They are needed to influence the intensity of light transmission and control the plane of polarization. To form the color, the presence of filters is used, the RGB palette is relevant in three colors, each pixel contains a combination of colors with different intensity indicators.
How are LED products different?
To draw conclusions and compare LED or OLED technologies, it is worth starting by examining the individual features of each of them. LED systems are among the most contrasting, but the final result greatly depends on the manufacturer. For example, there is VA or less contrast IPS, the presence of local dimming is of a certain importance. LED panel technologies work by transmitting light from LED arrays, and the backlight itself passes through the LCD panel with the presence of green, blue and red RGB pixels.
Light filters in all pixels create color and adjust brightness. The difference between LED and OLED lies in the fact that the first type of screens creates an imperfect shade of black, although the underexposure has become less pronounced. There are significant positive changes in 4K TVs with LCD technology. The emergence of other technologies was due to a previously existing flaw, as manufacturers wanted to increase the accuracy of color reproduction with contrast. There was a choice between OLED or QLED, but to call the LED / LCD technology in an advanced performance (in 4K HDR or SDR) imperfect or of poor quality is definitely impossible.
Features of OLED transmission
There is a popular question: LED or OLED, which is better of these two options? Let's take a closer look at the second technology. It has infinite contrast, absolute black levels, and it's easy to see significant differences from LED and other technologies. OLED displays operate on the basis of organic radiating conductors, while LCD TV screens work thanks to backlighting, while OLED screens glow on their own. The technology provides for the presence of extremely thin organic films, which are placed in the gap between two conductors. To emit light, a voltage is applied (within the range of 2-8 V). The appearance of light causes the image to appear.
QLED Technology
Also, OLED and QLED are often considered for comparison, what is the difference? Backlight with the QLED designation emits a beam of light with a constant length. The flow of light is directed to the layer with the presence of quantum dots, as a result of excitation they create light with a limited wavelength (a wave of a certain color is taken into account). The points have the indicators set by the manufacturer - at 3 nm it is possible to obtain a blue color, 2.5 nm - green, and so on. At the same time, there is a basic RGB-scheme, where the offset of the color streams is applied to obtain white, and then the color is supplied to the LCD matrix. The technology is similar to LED, since the color solution for each of the pixels is formed separately. VA-panels do not provide for local dimming, therefore there are no significant opportunities for working with contrast, in this parameter the technology is inferior to LED LCD.
Black Contrast and Reflection
TVs LED, OLED, QLED have significant differences in black reproduction and contrast. When considering LCD TVs, it all depends on the panel and the presence / absence of technology for dimming local action. The OLED version of the TV almost reaches the ideal in black level reproduction, the corresponding contrast reproduction possibilities are simply endless. For the manufacture of modern QLED TVs, VA panels are usually used, the situation is similar with LCD products (but there may be other options). Such models exceed the capabilities of IPS products and show black better.
As for LED TVs, they have a special type of matrix backlighting, due to which the contrast is increased. And the image on such TVs will be much richer and brighter than LCDs.
If you need perfect darkening of the desired areas, better reproduction of blacks or excellent contrast values, then OLED products cannot be worse than QLED or LCD TV, regardless of the date of issue and the type of panel. But take into account the rather high price for most OLED screens, you often have to look for an alternative. You can choose among the best 4K HDR LED TVs when using VA panels. Modern technology is capable of handling black reproduction at 0.016 to 0.020 nits.
4K-LED TVs are also acceptable, but here it is worth paying special attention to the presence of a type VA display, in which case manufacturers will offer a contrast ratio of 4000: 1 or with a higher level. QLED or OLED - which is better for black? QLED models are not as good as OLED models, although they have a plus in the VA panel. This avoids the risk of poor quality transmission. LCD TVs reproduce extremely deep blacks, which is only typical for premium 4K TVs. But even the most leading and expensive models fail to achieve the indicators that OLED displays are capable of, since any of the pixels is deactivated, including if everything around it glows. IPS 4K TVs can be called standard, they are much inferior in black transmission, when compared, the difference will be seen about 4 times (in contrast to black), this applies to the most advanced HDR products.
Comparison of the brightness of TVs with different technologies
The question of which is better than LED, QLED or OLED in terms of brightness is less significant than when considering contrast with black ... The reason is the ability to compensate for the lack of bright colors due to deep black tones. They enhance the perception of brightly colored reflections on the screen. At the same time, there are some competitions between the manufacturers of equipment and they concern precisely unprecedented heights in terms of the level of brightness of the panels.
In terms of brightness, QLED panels and LCD products are in the lead, among the most advanced options, an indicator from 1400 to 2000 nits is achieved. These are really high features that bring the viewer as close as possible to the greatest realism (as much as possible for a home format). At the same time, most LCD TVs in the mid-price segment have an indicator of only 400-500 nits, while 4K LCD / LEDs have almost no indicators, more than 500-700 nits. And also when adding HDR to increase contrast.
So, how is OLED different from QLED? Any QLED TV is top-end, so they have much higher brightness - from 1000 nits and above. For example, the Samsung Q9F delivers nearly 2000 nits in 10% of the screen area. This can only be compared to the Sony ZD9 LCD 4K TV, its performance is similar.
It is harder to consider the brightness of OLED products as LEDs are more limited, but at the expense of ideal black levels, much needed contrast is created. That way, even less vivid colors will look impressive than on a QLED LCD or LCD. LG's early OLED TVs can only handle 300 nits of brightness, and only leading tech like the LG OLED65W7V can produce 1000 nits. At the moment, OLED TVs are still the best in terms of brightness.
Color rendering in LED, QLED, OLED
Determining the difference in color rendition is not easy, since the process is the same for all TVs. During the period of operation of the increasing list of HDR shades, premium 4K TVs with LCD and OLED displays cope with a gamut coverage of about 9/10 DCI-P3, resulting in rich and pronounced shades. Most OLED products and all QLED devices are multi-HDR compliant and deliver high levels of color. But if you look, how LED differs from OLED and QLED, then QLED from Samsung with the presence of quantum dots stands out significantly. Such a system allows you to create the most impressive reproduction of the color palette. Other high quality products are somewhat inferior in capabilities. At the same time, OLED TVs show colors more natural, emphasizing them with blacks, increasing brightness. This principle bypasses the TOP level of LED products.
Motion Blur Level
When moving, objects at 4K often show blurry, the reason is the need for a sharp change in the color of the pixels used. The level of blur is influenced by the speed of color correction and the response time of pixels, either smooth processing or blurring, which is rather unpleasant to look at, will be provided. Less blur can be predicted when comparing response times, there are significant differences in LED TVs. No blur or low performance can provide premium 4K HDR LED products, but a number of other models are prone to significant motion blur.
The excellent performance of QLED TVs is possible due to the control of the rapid changes in pixel colors, especially this indicator is noticeable with the reduced response time, taking into account the basic indicators of LED products. So far, OLED has not surpassed in terms of lack of blur