Comparison Hisense 75U7KQ 75 " vs TCL 75C845 75 "

— 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 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 maximum brightness of the image provided by the TV screen.

The image on the screen should be bright enough so that you do not have to strain your eyes unnecessarily to view it. However, too high brightness is undesirable — it will also lead to fatigue. The optimal brightness level depends on the surrounding conditions: the more intense the ambient light, the brighter the TV screen should be. So, on a sunny day, the screen may have to be “turned up” to the maximum, and in the evening, in dimmed light, a relatively dim image will be more comfortable. In addition note that large screens require higher brightness, since they are designed for a greater distance from the viewer.

Thus, the higher the number in this paragraph, the greater the margin of brightness this model has, the better it will show itself in intense ambient light. The lowest indicator sufficient for more or less comfortable viewing in any conditions is 300 cd/m² for models with a diagonal of up to 32", 400 cd/m² for models in the range of 32 – 55" and 600 cd/m² for large screens of 60" and more. In this case, the brightness margin anyway will not be superfluous. But with lower indicators, you may have to darken the room somewhat for comfortable viewing.

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.

The highest frame rate supported by the TV.

Note that in this case we are talking specifically about the screen’s own frame rate, without additional image processing (see “Index of dynamic scenes”). This frequency must be no lower than the frame rate in the video being played - otherwise there may be jerks, interference and other unpleasant phenomena that degrade the quality of the picture. In addition, the higher the frame rate, the smoother and smoother the movement in the frame will look, and the better the detail of moving objects will be. However, it is worth noting here that playback speed is often limited by the properties of the content, and not by the characteristics of the screen. For example, films are often recorded at a frequency of only 30 fps, or even 24 - 25 fps, while most modern TVs support frequencies of 50 or 60 Hz. This is enough even for viewing high-quality content in HD resolutions (speeds above 60 fps in such video are extremely rare), but there are also “faster” screens on the market: 100 Hz, 120 Hz and 144 Hz. Such speeds, as a rule, indicate a fairly high class of the screen; they also often imply the use of various technologies designed to improve the quality of dynamic scenes.

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 compatibility with special frame synchronization technologies used in AMD graphics cards.

You should pay attention to this parameter if you plan to use the TV as a gaming monitor for a PC or laptop with an AMD graphics adapter. Special timing technologies are used to match the screen refresh rate to the frame rate of the incoming video signal. Such a need arises for the reason that the frame rate issued by the graphics card can “float” when the load on the video adapter changes (this is especially true for demanding games); and if this frequency does not match the screen refresh rate – tears and other unwanted artifacts appear on the image.

The AMD technology used to eliminate this effect is called FreeSync. Nowadays, it is presented on the market in three versions — the original FreeSync and two extended ones:

– AMD FreeSync Premium Pro. The most advanced and functional version, formerly known as AMD FreeSync 2 HDR. In addition to refresh rate sync, it also includes support for HDR (see above), output at a frame rate of at least 120 Hz at Full HD resolution, as well as low frame rate compensation (LFC). The essence of LFC is that when the frame rate of the original video signal falls below the minimum frequency supported by the screen, the same frame is displayed on the screen several times, which allows to maintain the maximum smoothness of the “picture”.

— AMD FreeSync Premium. A somewhat s...implified version compared to FreeSync Premium Pro. It does not provide working with HDR, otherwise it is completely similar.

The brand of the speaker system installed in the TV.

This item is indicated if the TV is equipped with advanced sound system, which is noticeably superior in quality to conventional speakers. Such information further emphasizes the high level of the device. At the same time, the specifications usually do not contain the full name of the speaker system, but only the brand name — for example, Bang & Olufsen, Harman Kardon, JBL, etc.: even such information is quite enough in this case.