Comparison LG 55SM8200 55 " vs LG 55SM8600 55 "

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.

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 TV's connectivity is based not only on wireless technologies (described above), but also on a wired connection. In particular, video transmission can be carried out through VGA, Component, Composite, SCART connectors. Some of them also provide sound transmission, in addition to which there may be a mini-Jack (3.5 mm). and other ports for interconnection with external devices. More about them:

— USB. Connector for connecting external peripheral devices. The presence of USB means at least that the TV is capable of playing content from flash drives and other external USB media. In addition, there may be other ways to use this input: recording TV programs to external media, connecting a WEB camera (see same paragraph), keyboard and mouse to use the built-in browser and other software, etc. The specific set of options depends on the functionality of the TV, it should be specified separately in each case.

— Card reader. A device for working with memory cards, most often in SD format. The main use of the card reader is to play content from such cards on a TV; such an opportunity is especially convenient for viewing materials from photo and video cameras — it is in such devices that memory cards are w...idely used. There may be other ways to use this function — for example, recording from the broadcast or even exchanging files between the card and the TV's storage. It is worth bearing in mind that SD cards have several subtypes — original SD, SD HC and SD XC, and not all of them may be supported by the card reader.

— LAN. Standard connector for wired connection to computer networks (both local and the Internet). Mostly found in models with Smart TV support (including Android TV devices; see related paragraphs). A wired connection is less convenient than Wi-Fi, not as aesthetically pleasing, so manufacturers place more emphasis on a wireless connection, as a result of which the speed indicators of the LAN connector are not indicated, and in some cases may be unacceptable for 4K broadcasts.

— VGA. Analogue video input, also known as D-sub 15 pin. Initially, the VGA interface was developed for computers, but due to the emergence of more advanced standards like HDMI (see below) and technical limitations (the maximum resolution is only 1280x1024, the inability to transmit sound), it is considered obsolete and is used less and less. So it makes sense to specifically look for a TV with such a connector mainly in cases where it is planned to be used as a monitor for an outdated computer or laptop.

— Component. Video interface with 3 connectors, each of which is responsible for its part of the video signal. This separation provides high bandwidth and noise reduction, making the component input the most advanced analogue video interface available today. So, it is capable of working with HD, and in terms of image quality it significantly surpasses S-Video and composite connector, closely approaching HDMI (see below).

— Composite. Combined analogue audio/video interface, it is this connector that is usually called the A/V input. Actually, there are usually three connectors in the composite interface — separately for video and the left/right channel of stereo sound (on TVs with one speaker that do not support stereo, one of the audio connectors is missing). The image quality when working through such an input is not high, and HD formats are not supported at all; on the other hand, the composite interface is extremely widespread not only in modern, but also in outdated equipment like VHS video recorders.

— SCART. The large universal multimedia connector, the largest connector used in today's consumer-grade video equipment. Works mainly with an analogue signal, which is why it is considered obsolete; however, still not falling into disuse. One of the reasons for this "longevity" is versatility: SCART does not have its "own" signal format, this standard only describes the connector. In fact, having the appropriate cables, you can connect different types of incoming signals to such an input — composite, S-Video, etc. Moreover, it is technically possible for such a connector to work as an output (for the same signal types). However the specifications of SCART connectors in different TVs may be different, so a specific list of compatible interfaces needs to be specified separately.

— COM port (RS-232). A connector originally developed for computer technology. It is used as a control on TVs: by connecting the device to a computer, you can control TV parameters and various settings, sometimes quite specific and inaccessible when using a conventional remote control.

— Mini-Jack (3.5 mm). A connector most commonly used as an analogue audio (line) input. One of the options for using such a connector is to connect audio for a video signal transmitted via VGA, S-Video (see above) or another interface that does not support audio transmission. However, with the appropriate cable, any audio source can be connected to the 3.5 mm mini-Jack port, including a mobile device like a smartphone or a pocket player. In this case, the sound can be played both through the speakers of the TV, and on external speakers connected to it. Another option for using this input is to connect a microphone for chatting via Skype.

The electrical power normally consumed by the TV. This parameter strongly depends on the screen size and sound power (see above), however, it can be determined by other parameters — primarily additional features and technologies implemented in the design. It is worth noting that most modern LCD TVs are quite economical, and most often this parameter does not play a significant role — in most cases, power consumption is about several tens of watts. And even large models with a diagonal of 70 – 90" consume about 200 – 300 W — this can be compared with the system unit of a low-power desktop PC.

The energy efficiency class characterizes how efficiently the TV consumes electricity. Initially, the classes were denoted by simple Latin letters — A (the most efficient), B, C. However, later improved classes “A+ ”, “A++”, etc. appeared (the more "pluses", the more efficient the device).

The energy class will generally affect the price accordingly, but this difference will eventually pay off with lower electricity bills.