Resolution
Screen resolution - its size in pixels horizontally and vertically. Other things being equal, a higher resolution provides better image quality, but such a screen costs more and requires relevant content.
The set of resolutions found in modern TVs is quite extensive, but they can be roughly divided into several groups:
HD,
Full HD,
Ultra HD 4K, Ultra HD 5K and
Ultra HD 8K. Here are the main features of each option:
— HD. Screens designed for HD 720p. The standard frame size in such a video is 1280x720, however, for a number of reasons, most HD TVs have somewhat larger sizes — 1366x768. In addition, this category usually includes models with resolutions from 1280x768 to 1680x1050, as well as 1024x768 screens. In general, HD 720p resolutions are mostly found on low-cost TVs with relatively small screens.
— Full HD. TVs designed for Full HD 1080p video, with a frame size of 1920x1080. Most models from this category have exactly this screen resolution — 1920x1080; other options are noticeably less common — in particular, 1920x1200 and 2560x1080. In general, Full HD screens provide good detail at a relatively low cost, making them extremely popular in mid-range models and inexpensive large-format TVs.
— Ultra HD 4K. This format provides different options in resolutions, however, for TVs, the actual stan
...dard is 3840x2160, other options are almost never found. In general, this is a fairly high resolution, which is typical mainly for premium models; a common feature of such models is the large size — from 40" and more.
— Ultra HD 5K. The Ultra HD image format is more advanced than 4K, but it is extremely rare in TVs — these are mainly ultra-wide models with a resolution of 5120x2160.
— Ultra HD 8K. A standard that assumes a size of about 8K pixels horizontally; one of the options for this resolution, found in TVs — 7680x4320. Thus, UHD 8K is twice the size of 4K on each side and four times the total number of pixels, resulting in extremely sharp and detailed images. On the other hand, such screens are very expensive, despite the fact that nowadays even 4K is already considered a very advanced standard. Plus, there are not many video devices and content that meet this standard. Therefore, 8K TVs are still extremely rare, they include mostly high-end flagship models with a size of at least 65".Dynamic scene index
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.
Audio decoders
A decoder can be broadly described as a standard in which digital audio (often multi-channel) is recorded. For normal playback of such sound, it is necessary that the corresponding decoder is supported by the device. Dolby Digital and DTS were the first in multi-channel decoding, gradually improving and introducing new features. The final stage for 2020 is Dolby Atmos and DTS X decoders.
–
Dolby Atmos. A decoder that uses not a rigid distribution of sound across channels, but the processing of audio objects, due to which it can be used with almost any number of channels on a reproducing system — the sound will be divided between channels so that each audio object is heard as close as possible to its proper place. When using Dolby Atmos, ceiling speakers (or speakers facing the ceiling) are highly desirable. However, in extreme cases, you can do without them.
— DTS X. An analogue of the Dolby Atmos described above, when the sound is distributed not through individual channels, but through audio objects. The digital signal contains information about where (according to the director's intention) the object audible to the user should be and how it should move, and the processor of the reproducing device processes this information and determines exactly how the sound should be distributed over the available channels in order to achieve the required localization. Thanks to this, DTS X is not tied to a specific number of audi
...o channels — there can be as many as you like, the system will automatically divide the sound into them, achieving the desired sound. Also note that this decoder allows you to separately adjust the volume of dialogues.
