Comparison TCL 43P638 43 " vs TCL 43C635 43 "

— Smart TV (own system). The operating system of the TV is represented by the manufacturer's proprietary software shell. Usually, such operating systems have an attractive and understandable menu, similar to a traditional Smart TV. A proprietary operating system is developed by the manufacturer for the hardware resources of a particular TV model or a whole line. But, as practice shows, compared to the classic Smart TV, the functionality of its own system often has significant limitations, and the system itself, in fact, is a stripped-down version of a full-fledged Smart TV.

— Smart TV (Android AOSP). This type of operating system is a modification of the popular Android OS, mainly notable for being open source. It is a versatile operating system that gives the user much more freedom to create changes and customizations within the system itself. At the same time, the installation and stability of certain applications on this platform are not guaranteed, and the overall system management was not specially “tailored” for large screens, which may cause some inconvenience. First of all, such solutions will arouse interest among users who understand the features of the Android OS, like to customize and control everything for themselves, and have time for this.

— Android TV. TVs of this type boast full-fledged Android TV software, specially adapted to work on...large screens. In accordance with the name, it is a kind of Android OS, specially “sharpened” for TVs / projectors, etc. In addition to the common features of all “Androids” (such as the ability to install additional applications, including even games), it has a number of special features: optimized interface, integration with smartphones (including the ability to use them as a remote control), voice search, etc. Thanks to this, TVs with this feature are significantly superior in functionality to models with a “regular” Smart TV. Of course, a dedicated processor, graphics subsystem and memory are provided for the operation of a multifunctional OS, and the presence of such hardware resources is reflected in the total cost of the TV. Given the same optical design, models with Android TV will cost more than classic devices with a simple multi-line menu.

— Google TV. Rebranding of the Android TV platform for TVs and smart set-top boxes, or rather, a new shell on top of the operating system under the sign of the “green droid”, introduced since 2021. Among the innovations, it has a redesigned user interface, an improved knowledge base that more efficiently distributes content by genre and collects search information from the entire list of installed applications and subscriptions. The voice assistant now understands the needs of the audience better and provides a detailed list of what was found. A separate tab in the interface contains live broadcasts of current events, whether it be sports events or a rocket launch to Mars. Among other things, the aspects that involve the use of TV as a command post for managing a single ecosystem of a “smart” home have been improved in the system.

The type of matrix used in the TV. Among them, OLED, QLED, QD-OLED and NanoCell deserve the most attention, which are found in TVs of the relevant price category. Now more about each of them and other more classic options:

— OLED. TVs with screens that use organic light-emitting diodes — OLED. Such LEDs can be used both to illuminate a traditional LCD matrix, and as elements from which a screen is built. In the first case, the advantages of OLED over traditional LED are compactness, extremely low power consumption, backlight uniformity, as well as excellent brightness and contrast ratios. And in matrices, consisting entirely of OLED, these advantages are even more pronounced. The main disadvantages of OLED TVs are the high price (which, however, is constantly decreasing as the technology develops and improves), as well as the susceptibility of organic pixels to burn-in during long-term broadcast of static images or pictures with static elements (TV channel logo, information panel, etc.).

— QLED. TVs with screens using "quantum dot" technology — QLED. Such screens differ from conventional LED matrices in the design of the backlight: multilayer colour filters in such a backlight are replaced with a thin-film light-transmitting coating based on nanoparticles, and traditional white LEDs are replaced with blue ones. This a...llows to achieve a significant increase in brightness and colour saturation at the same time as improving the quality of colour reproduction, besides, it reduces the thickness and reduces the power consumption of the screen. The disadvantage of QLED matrices is traditional — the high price.

— QD-OLED. A kind of hybrid version of matrices that combine “quantum dots” (Quantum Dot) and organic light-emitting diodes (OLED) in one bottle. The QD-OLED modification was introduced by Samsung at the end of 2021 in response to advanced OLED panels from LG. The technology takes the best from QLED and OLED: it is based on blue LEDs, self-luminous pixels (instead of external backlighting) and “quantum dots”, which play the role of colour filters, but at the same time practically do not attenuate the light (unlike traditional filters) . Thanks to the use of a number of advanced solutions, the creators managed to achieve very impressive characteristics, significantly superior to many other OLED matrices. Among them are high peak brightness from 1000 nits (cd/m²), excellent contrast and black depth, as well as colour coverage of over 90% according to the BT.2020 standard and more than 120% according to DCI-P3. Such matrices are found mainly in flagship TV panels.

— IPS. A type of matrix originally designed for high quality colour rendering. Indeed, IPS screens produce bright and rich colors, have a good colour gamut, and demonstrate wide viewing angles. The initial disadvantage of this technology was the low response time, but in modern modifications of IPS this point has been practically eliminated. Matrices of this type are very popular in the advanced budget and mid-price segment of TV panels.

— *VA. In this case, we mean one of the varieties of VA (Vertical Alignment) type matrices - MVA, PVA, Super PVA, etc. Specific varieties may vary slightly in properties, but they all have common features. In fact, *VA matrices are a more affordable alternative to IPS panels: they are relatively inexpensive, provide fairly good colour reproduction and viewing angles of up to 178°. The main disadvantage of such screens is the long response time, but in modern models this has been practically eliminated thanks to the constant improvement of technology. *VA matrices are used in TVs that are positioned as functional and at the same time affordable models.

— PLS. In fact, it is one of the varieties of the IPS matrices described above, developed by Samsung. According to the manufacturer, in such matrices it was possible to achieve higher brightness and contrast than in traditional IPS, as well as to slightly reduce the cost.

— NanoCell. Matrix based on quantum dots. This type of matrix is used in LG TVs and was first introduced in 2017. NanoCell matrices use the structure of classic LCD displays. But unlike the latter, they use so-called quantum dots instead of the classic general backlight, which provide monochromatic light. NanoCell technology reduces power consumption while increasing colour gamut and viewing angle. It is worth noting separately that NanoCell matrices are not the only ones using quantum dot technology. Similar solutions are offered by: Samsung (QLED matrix), Sony (Triluminos matrix), Hisense (ULED).

— Edge LED — side backlight of the matrix. In this case, the LEDs are distributed around the perimeter of the screen. To evenly distribute the backlight, the background of the matrix has a special reflector. An important advantage of TVs with Edge LED backlighting is the minimum thickness of the device. Among the shortcomings, one can note the presence of glare at the edges, which appear under certain conditions. Glare may be visible in scenes where dark hues predominate.

— Direct LED — rear matrix backlight. In this case, the LEDs are evenly distributed over the entire screen area. The Direct LED backlight makes the image contrast and bright at the same time. TVs with this technology have good colour reproduction. Among the shortcomings can be noted increased power consumption and increased dimensions. Additionally, such TVs have a large delay (Input lag), which is why Direct LED backlit screens are poorly suited for dynamic games.

— FALD (Full-Array Local Dimming) is a backlight technology widely used in LG TVs. A close analogue of FALD is the Direct LED backlight. The LEDs are also evenly spaced across the entire surface of the matrix, but FALD technology provides a bright, colour-rich image with high contrast. Another distinctive feature of FALD is the ability to reproduce natural blacks. When black is displayed on the screen, the LEDs are turn...ed off in groups, by sector, which allows to make black extremely saturated. Of course, the abundance of LEDs on the matrix makes the TV more massive, and at the same time heavy. The appetite for electricity in such models is above average.

— Mini LED. Screen backlight system on a substrate of reduced LEDs (hence the Mini prefix). On the same plane of the TV panel, the number of LEDs has increased several times, if we draw parallels with traditional LED systems. As a result, the canvas with Mini LED backlight has many times more local dimming zones of the picture (Local Dimming), which is necessary for the correct operation of the extended dynamic range image technology. For playing HDR content, Mini LED systems are much better than ordinary LCDs.

— Dual LED. Proprietary backlight system used in Samsung TVs. The technology involves illuminating the image on the screen with two types of LEDs: one emits light in a cold spectrum, the other in a warm one. The Dual LED enhances colour reproduction and enhances detail contrast by adapting the colour tone of the picture according to the content on the screen.

The type of coating used on the TV screen.

— Matte. Historically, the first type of coating for LCD screens, which is often found today. Screens with such a coating generally have average characteristics of brightness, saturation and colour reproduction quality, in terms of these indicators they are inferior to glossy counterparts. However, the matte coating has one important advantage: it has virtually no glare from ambient light. In some situations, this can be an important advantage — for example, if the TV is installed opposite the window. And for some users it is more pleasant to look at the screen without glare, albeit relatively dim.

— Glossy. A coating designed to improve the brightness and colour quality of the visible image compared to matte screens. The creators have managed to achieve this goal: "glossy" screens really provide rich, vibrant colours and a brighter image. The key disadvantage of such screens is the appearance of glare from ambient light on them — this can ruin the whole viewing experience. Because of this, the classic glossy coating is practically not used today, anti-glare solutions have taken its place (see below).

— Glossy (anti-glare). Modification of the glossy coating, created, as the name implies, in order to eliminate the main drawback of the classic gloss — glare from external lighting. This is not to say th...at such screens do not glare at all, but there are much less reflections on them than on ordinary glossy ones. As for the image quality, it is at least not much worse, and often even better (especially since such coatings are constantly being improved). Thanks to all this, most modern TVs of all price categories are equipped with anti-glare screens.

The level of static contrast provided by the TV screen.

Contrast in a general sense is the ratio in brightness between the brightest whites and the darkest blacks that the screen can produce. Other things being equal, the higher the screen contrast, the better the quality of colour reproduction and detail, the lower the likelihood that it will be impossible to see details in too bright or too dark areas of the image. Static contrast, on the other hand, describes the maximum difference in brightness that can be achieved within one frame without changing the brightness of the image — this is its difference from dynamic contrast (see below).

The values of static contrast are much lower than those of dynamic, but this characteristic is the most "honest". It is on it that the properties of the image seen on the screen at a particular moment depend, it is describes the basic properties of the screen, without taking into account the software tricks provided by the manufacturer in the hardware of the TV.

The response time can be described as the maximum time required for each pixel of the screen to change brightness, in other words, the longest time from the receipt of a control signal to the pixel until it switches to the specified mode. The actual switching time may be less — if the brightness changes slightly, it can be calculated in microseconds. However, it is the longest time that matters — it describes the guaranteed response speed of each pixel.

First of all, the frame rate is directly related to the response time (see the relevant paragraph): the lower the response time, the higher the frame rate can be provided on this sensor. However, the actual frame rate may be less than the theoretical maximum, it all depends on the TV. Also note that the overall image quality in dynamic scenes depends primarily on the frame rate. Therefore, we can say that the response time is an auxiliary parameter: the average user rarely needs this data, and in the specifications they are given mainly for advertising purposes.

Dynamic Scene Index (DSI) provided by the TV screen.

DSI is a rather specific parameter that can be called "visible framerate". Its appearance is due to the fact that a high frame rate is highly desirable for dynamic scenes — it provides smooth images and good detail of moving objects. However, for technical reasons, it is not possible to achieve indicators above 200 Hz in most screens. In order to remedy the situation, manufacturers use special technologies that create the effect of increasing the frame rate.

Such technologies may have different names, but they have the same principle of operation — inserting additional frames between the "own" frames of the video being played. And the dynamic scene index describes the overall effectiveness of such technology used in a TV. For example, a DSI of 200 Hz means that the image quality on the screen approximates a frame rate of 200 Hz, although the actual frame rate is often as low as 50-60 Hz.

In the most advanced models, the dynamic scene index can be up to 3000 Hz, and options above 3000 Hz are considered to be TVs with a high dynamic scene index. However, it is worth noting that such specifications are more of an advertising ploy than a real advantage: in fact, the threshold for human perception is 400 – 500 Hz, a further increase in the DSI does not give a clearly visible improvement in the image.

TV support for high dynamic range technology — HDR.

This technology is designed to expand the range of brightness reproduced by the TV; Simply put, an HDR model will display brighter whites and darker blacks than a regular TV. In fact, this means a significant improvement in colour quality. On the one hand, HDR provides a very "live" image, close to what the human eye sees, with an abundance of shades and tones that a normal screen cannot convey; on the other hand, this technology allows to achieve very bright and rich colours.

However for the full use of this feature, you need not only an HDR TV, but also content (movies, TV broadcasts, etc.) that was originally created for HDR. Also note that there are several different HDR technologies that are not compatible with each other. Therefore, when buying a TV with this feature, it is highly advisable to clarify which version of HDR it supports (HDR10, HDR10 + or Dolby Vision). And the following are found:

— HDR10. Historically the first of the consumer HDR formats, less advanced than the options described below but extremely widespread. In particular, HDR10 is supported by almost all streaming services that provide HDR content, and it is also common for Blu-ray discs. Allows to work with a colour depth of 10 bits (hence the name). At the same time, devices of this format are also compatible wi...th content in HDR10+, although its quality will be limited by the capabilities of the original HDR10.

— HDR10+. An improved version of HDR10. With the same colour depth (10 bits), it uses the so-called dynamic metadata, which allows transmitting information about the colour depth not only for groups of several frames, but also for individual frames. This results in an additional improvement in colour reproduction.

– Dolby Vision. An advanced standard used particularly in professional cinematography. Allows to achieve a colour depth of 12 bits, uses the dynamic metadata described above, and also makes it possible to transmit two image options at once in one video stream — HDR and standard (SDR). At the same time, Dolby Vision is based on the same technology as HDR10, so in modern video technology this format is usually combined with HDR10 or HDR10+.

The TV's support of one or the other colour enhancement technology.

Such technologies usually involve image processing in software to provide brighter and/or more accurate colours. Specific processing methods may be different, some manufacturers do not specify technical details at all, limiting themselves to advertising statements. The effect of using such technologies can also vary: in some cases it is clearly visible, in others it is almost absent, depending on the features of the picture. It is also worth saying that this feature, usually, needs to be turned on manually in the TV menu (accordingly, it can be turned off if desired).