Comparison Sony KDL-43WF805 43 " vs Sony KDL-42W705B 42 "

The optimal size of the TV depends primarily on the distance from which it is planned to watch. If the diagonal on the screen is too small, it will be difficult to see the details, you will have to strain; if too large, the image will be much larger than the field of view, which is also undesirable. The best option is the situation when the distance to the TV corresponds to 3 - 4 of its diagonals: for example, for a size of 32 "(80 cm), the recommended distance is about 2.5 - 3 m.

The size of the diagonal of the screen affects both the cost of the TV and its general equipment. So, among models smaller than 32" there are often TVs without Smart TV and other advanced features; TVs for 32 - 55" can be both quite simple and advanced; and a large screen, more than 55", in most cases is combined with extensive additional functionality.

Now the following popular diagonals are on the market: 32 ", 39 - 40", 43", 49", 49 - 50", 55", 65", 75" and more than 80".

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 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+.

TV support for one or another brightness / contrast enhancement technology.

Usually, in this case, software image processing is implied, in such a way as to improve brightness and/or contrast (if necessary). Specific processing methods may be different — in particular, in some cases we are actually talking about turning standard content into HDR (see above), and some manufacturers do not specify technical details at all. The effectiveness of different technologies can also be different, and besides, it is highly dependent on the specific content: in some cases, the improvement will be obvious, in others it may be almost imperceptible. Also note that this feature is not always useful, so in most models it is turned off.

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).

The nominal power of the sound produced by the TV's sound system.

The larger the screen and the greater the estimated distance to the viewer, the more powerful the sound system must be in order to be heard normally. Manufacturers take this moment into account, moreover, most often they also provide a solid volume margin. So if a TV is bought for home viewing in a quiet, calm environment, you can not pay much attention to the sound power: it is guaranteed to be enough for such a usage. It makes sense to specifically look for models with high-power speakers for a noisy environment — for example, a cafe or other public space. Detailed recommendations on this matter can be found in special sources, but here we note that even in such cases, connecting external speakers can be a good alternative.

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.

The ability to display on the TV screen "pictures" from several sources at once. Usually, in the picture-in-picture mode, a small window is displayed in the background of the main image (or several such windows), which is displayed in full screen, in it you can see an additional image. One of the most popular ways to use this “multitasking” is to skip commercial breaks in TV broadcasts: for this time, you can switch the main image to a more interesting channel, and leave the ad in the auxiliary window to not miss the end of the commercial and continue watching. It is worth considering, however, that the images for each window must come from different sources — in other words, it will not work to turn on two channels at the same time from one tuner.