Comparison Liberton 22HE1FHDTA 22 " vs Ergo LE21CT5500AK 21 "

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 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.

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.

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.

— Coaxial (S/P-DIF). An interface for transmitting audio in digital format, which allows to transmit multi-channel audio via a single cable with an RCA connector (“tulip”). In terms of resistance to interference, this standard is somewhat inferior to the optical one (see below) — this is due to the fundamental differences between these interfaces. On the other hand, electrical cable is more reliable than optical fibre and is not as sensitive to pressure and bending.

— Optical. An output for transmission of a digital audio signal on a fibre optic cable; allows the transmission of multi-channel audio. Notable for its complete insensitivity to electromagnetic interference. On the other hand, fibre optic cable is quite fragile, it must be protected from bending and strong pressure.

— Mini-Jack (3.5 mm) for headphones. Standard 3.5mm headphone jack. Headphones can come in handy if you need to keep quiet and you can’t use the TV speakers – for example, at a later time of the day; or vice versa, if the environment is noisy and the sound of the TV is hard to hear. Most modern "ears" use a mini-Jack plug, so this connector is the standard headphone output in TVs. And in some models, this output can also be used as a linear output — for example, to connect individual speakers, a sound recording device, etc.

— Subwoofer. A separate output for connectin...g a subwoofer to a TV is a speaker for reproducing low and ultra-low frequencies. Audio systems without subwoofers usually reproduce these frequencies quite poorly. The use of subwoofer allows you to achieve the most deep and rich sound, which is especially important when watching movies with a lot of special effects or high-quality recordings from concerts. At the same time, it is worth noting that such outputs are quite rare in TVs: it is assumed that a full-format external audio system is more suitable for a demanding listener than a separate subwoofer.

— Line. Standard analogue audio interface; usually, provides the transmission of two-channel stereo. It is used primarily to connect active speakers and other audio equipment (for example, audio receivers or power amplifiers) to TVs. It can use different types of connectors, but most often it provides either a 3.5 mm mini-Jack or a pair of RCA jacks for tulip cables. Note that it is a separate line output that is meant here; in some models, this function can be performed by a 3.5 mm headphone jack (see above), but for them the presence of a line-out is not indicated.

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.