Size
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".
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".Brightness
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.
Static contrast
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.
Response time
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.
HDMI
The number of HDMI inputs provided in the design of the TV.
HDMI is a comprehensive digital interface that allows high-definition video and multi-channel audio to be transmitted over a single cable. It is widely used in modern HD equipment — in fact, the presence of such an output is mandatory for modern media centers, DVD players, etc. Therefore, LCD TVs in the vast majority of cases are equipped with at least one HDMI port. And the presence of several such ports allows you to simultaneously connect several signal sources and switch between them; in some models, the number of HDMI can reach
4 or even more. At the same time, some manufacturers use technologies that allow you to control devices connected to the TV via HDMI from a single remote control.
HDMI version
About the interface itself, see above, and its different versions differ in maximum resolution and other features. Here are the options found in modern TVs:
— v 1.4. The oldest of the current versions, released in 2009. However, it supports 3D video, capable of working with resolutions up to 4096x2160 at 24 fps, and in Full HD resolution, the frame rate can reach 120 fps. In addition to the original v.1.4, there are also improved modifications — v.1.4a and v.1.4b; they are similar in terms of basic features, in both cases the improvements affected mainly work with 3D content.
– v 2.0. Significant update to HDMI introduced in 2013. In this version, the maximum frame rate in 4K has increased to 60 fps, and the audio bandwidth has increased to 32 channels and 4 separate streams simultaneously. Also from the innovations, we can mention support for the ultra-wide format 21:9. In the v.2.0a update HDR support was added to the interface capabilities, in v.2.0b this feature was improved and expanded.
— v 2.1. Despite the similarity in name to v.2.0, this version, released in 2017, was a very large-scale update. In particular, it added support for 8K and even 10K at speeds up to 120 fps, as well as even more expanded features for working with HDR. Under this version, its own cable was released — HDMI Ultra High Speed, all
HDMI 2.1 features are available only when using cables of this standard, although basic functio
...ns can be used with simpler cords.Additional inputs
The TV's connectivity options are based not only on wireless technologies (described above), but also on a wired connection. In particular, additional video transmission can be carried out through
VGA,
composite AV 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 communication 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 widely used. There may be other ways to use this function — fo
...r 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.
– Composite AV input. Analogue input for video and audio transmission. Previously, it consisted of 3 RCA sockets (yellow for video, white and red for audio) and was connected to the equipment accordingly. Now in many models you can find an AV output, which is a single connector in the “headphone” format, to which a tee cable is already connected (check availability in the package).
— COM port (RS-232). A connector originally designed for computer equipment. In TVs, it is used as a service interface: for troubleshooting, updating firmware, adjusting TV parameters and various calibrations, integrating the TV into centralized remote control systems, etc. Note that the COM port may differ in shape and contact group in different TV models. It is often designated as RS-232C.Stand shape
— 2 separate legs.
Two legs as support are usually located on different sides of the lower face of the TV panel body. Such a design involves placing the TV on a large flat surface that extends along the entire lower side of the device. The TV is often more stable on two "legs" than on
one leg.
— 1 leg on the platform. A support for the TV with a round or rectangular platform, which is in contact with the surface of the TV panel (table, stand, etc.) with its entire plane.
— 1 leg with supports. Stands of this kind consist of a single leg and a base of various geometric shapes that holds the TV. This solution ensures reliable stability of the TV panel, and in terms of design, it is a stylish element of the design of the structure.
— Monolithic. A solid stand with two or more attachment points to the bottom of the TV and monolithic frames as a solid support for installing the TV panel on a flat surface of a table or stand.