Modern technology is developing rapidly. New TV models appear regularly, offering ever higher picture quality. The concept of "high definition television" emerged and firmly rooted, raising the bar of experience to a new level. The transition to all-digital TV broadcasting is just around the corner, providing superior detail and noise reduction. Therefore, it is quite natural that the question arises about replacing the home screen or buying an additional one.

There are more than 120 manufacturers and several thousand TV models in the world. Each company seeks to attract the buyer with new proprietary technologies and developments, which, in order to make the right choice, you need to understand. The purpose of this article is to help you choose your TV.

Screen type

First of all, you need to decide for what purpose the TV is being bought: whether you will watch news or broadcast programs, DVD or Blu-Ray movies, whether you will put it in the kitchen or bedroom. After all, a screen suitable for receiving a satellite signal in a living room and a TV set for watching movie discs are not at all the same thing. The living room usually contains most of the components of a home media system: a DVD or Blu-ray disc player, surround sound speakers, a satellite receiver, and more. The TV in the kitchen usually works for the background, in the bedroom it is needed to receive terrestrial cable and satellite TV broadcasts, and to view discs. Here you no longer need powerful sound and connection of additional devices. If a TV is needed for a nursery, consider the possibility of connecting game consoles, a camera or camcorder to it. When this issue is resolved, you can begin to understand the characteristics of the TV.

So, first you have to decide on the type of screen.

The following types of TVs are on the market today:

Liquid crystal (LCD, LCD);

Light-emitting diode (LED);

Plasma.

All of them have their advantages and disadvantages - we will consider them in more detail.

LCD TV

LCD-technology (eng. LCD - Liquid Crystal Display, "liquid crystal display") is by far the most widespread. An LCD screen is a matrix of many dots, called pixels. Each pixel is made up of three “subpixels” of red, green, and blue. Liquid crystals inside the elements are able to change their position in space under the influence of an electric field, passing or blocking light from the backlight lamps installed behind the matrix. When all three subpixels are fully transparent, the cell is white, and when opaque it is black. Halftones and shades are obtained by mixing the primary colors in the desired proportion. Thus, using a special microcircuit, you can control the transparency of each pixel and form an image.

The design feature of the LCD technology is the need for light to "overcome" a layer of liquid crystals, the transparency of which is not ideal. Therefore, to obtain sufficient brightness of the picture, it is necessary to install powerful lamps, which increases the price and power consumption of the device. The elements are not able to perfectly block the flow of light - the black on an LCD TV screen is not actually completely black.

Among the shortcomings, it is also necessary to note the distortion of colors and the loss of contrast, since the viewing angle of the LCD is not so wide. Because of this feature, LCD TVs could not gain popularity for a long time, but now, thanks to the efforts of the developers, the distortion has become almost invisible.

The advantages of LCD TVs include a wide range of models with different brightness (from 250 to 1500 cd / m2) and contrast (from 500: 1 to 5,000,000: 1). Thanks to this, the buyer can purchase a device that optimally combines the required image quality and affordable price. In addition, LCD TVs are lightweight and thin so they can be wall-mounted. But the biggest merit of liquid crystal technology is its massiveness. Due to large-scale production, prices for LCD TVs are now lower than other similar devices.

Also, LCD TVs have gained popularity for their versatility. LED TVs provide a comfortable viewing experience in almost any environment, so they are suitable for most rooms. By the level of contrast and color rendering, expensive LCD models can compete with plasmas, which allows them to take their rightful place, for example, in the living room of the Hi-End class.

LED TV

The difference between LED TVs (English LED - Light Emitting Diode, "light-emitting diode") from liquid crystal is only in the matrix backlight technology: instead of fluorescent lamps, LEDs are used, due to which LED TVs have a number of advantages over LCD.

An LED TV is capable of displaying more colors than a “tube” LCD TV, so the image looks more natural. The use of LEDs made it possible to reduce the thickness of the screen and reduce power consumption by up to 40%, compared to LCD. The brightness and contrast characteristics have also improved significantly.

The only drawback of this technology is its relative high cost. However, the advantages of LED TVs suggest that over time they will become leaders in this market.

Because LED TVs are based on liquid crystal technology, they are as versatile as LCDs. But due to its merits, LED TV will be more preferable than LCD when it comes to your living room.

Plasma TV

Plasma TV screen is also a matrix of small elements, but this technology is implemented in sealed cells filled with gas - neon or xenon. If, with the help of special transparent electrodes, an electric voltage is applied to the cell, then the gas inside it turns into a plasma state and begins to emit ultraviolet light. The rays fall on a phosphor layer applied to the cell wall, which, depending on its composition, emits red, green or blue light. The higher the applied voltage level, the more intensely the cell glows. Different shades of color are obtained by mixing the three primary colors. By controlling the voltage supplied to the cells, the electronic module forms an image on the plasma screen.

Thus, according to the principle of operation, the cells are similar to fluorescent lamps, that is, they have the property of self-luminescence, therefore a plasma TV has some advantages over LCD and LED.

Plasma TVs provide excellent picture contrast and are about 3 times brighter than most LCD and LED screens. After all, a pixel in an inactive state does not emit anything - it is really black, and the light emitted by it in an active state has a sufficiently high intensity. The use of phosphor makes the colors vivid and saturated. Plasma TVs, in comparison with LCD and LED, have a very fast response time.

Plasma technology has a number of specific design problems. The main one is the problem of the minimum cell size. Creating a small cell - actually a gas-filled glass flask with electrodes - is difficult. Therefore, the development of this technology runs counter to the development of other "matrix" visualization technologies: the diagonals of plasma TV screens have only recently reached 32 inches, while plasma screens with large diagonals (over 50 inches) have existed for quite a long time.

The availability of only models with large screen diagonals on sale has made plasma TVs the usual choice for buyers who want to get the most out of watching movies in bright, saturated color.

The main characteristics of the TV:

Screen diagonal;

Permission.

Advanced TV options:

Matrix response time;

Contrast;

Brightness;

Viewing angles;

Interfaces;

Additional functions.

Screen diagonal

Screen diagonal can be considered a fundamental characteristic of a TV. It directly affects its size, weight and price. Correctly selected screen diagonal largely determines the comfort and impressions obtained from viewing, therefore it deserves the closest attention when choosing.

Traditionally, the size of the diagonal of the screen is measured in inches and denoted, for example, like this: 32 ". It is easy to calculate it in centimeters: 1 inch = 2.54 cm.

In order for the viewing to be comfortable, the diagonal of the TV screen must necessarily correspond to the size of the room in which it is planned to be installed. The most common in the domestic market are screens ranging from 26 to 42 inches. For a TV in a living room, a large screen diagonal is very important, since the whole family or a group of guests can gather in this room at the same time, and each of those present must perceive the image clearly, without causing strain and eye fatigue. There can be many layouts, but in most cases a TV with a screen diagonal of 32 ”or more will be optimal for a living room.

For the kitchen and bedroom, it is better to choose a smaller TV, because the area of ​​these rooms is usually inferior to the area of ​​the living room. Studies show that the optimal diagonal of a TV screen should be about 3 times less than the distance at which it is supposed to be watched. If the TV is too large for a given room, the image on the screen will not be perceived as a whole. There may be some "graininess" of the picture and the jaggedness of the boundaries between objects. This is especially true for models with a plasma screen: when viewed at too close a distance, the image tends to "disintegrate", that is, individual pixels become noticeable. Therefore, for the kitchen, we recommend choosing a TV with a screen diagonal of 20-26 ", for a bedroom it can be slightly larger - up to 32".

Most 15-21 ”models have a D-Sub (sometimes referred to as“ VGA ”) or DVI port that allows you to connect your TV to your computer as a monitor.

Permission

Be sure to pay attention to the screen resolution. This characteristic is responsible for the quality and detail of the image.

The screen of any liquid crystal, LED or plasma TV consists of cells called pixels, the total number of which is called the screen resolution. It is expressed as two numbers, the first of which indicates the number of pixels horizontally and the second vertically, for example, 1920x1080. The high resolution screen allows the TV to display crisp images with plenty of detail and smooth lines without jaggies.

A 42 ”TV with a resolution of 1920 × 1080 will show a clearer picture than a TV with a resolution of 1366 × 768 with the same diagonal. The point is that having more pixels on the same screen area means that each of them is smaller.

Today, the best image quality available to the general consumer is provided by a relatively new digital television standard - HDTV or high definition television (HDTV).

HDTV (English "High-Definition TeleVision") is a set of high quality television broadcasting standards, which includes requirements for format, resolution and image formation method, as well as for sound quality.

High Definition Standards Formats:

720p: 1280 × 720 resolution, progressive scan;

1080i: 1920 × 1080 resolution, interlaced;

1080p: 1920 x 1080 resolution progressive scan.

Scan, denoted by the Latin letters "i" and "p", is a way of displaying a frame on the screen. Unlike Interlacing Scan, Progressive Scan provides better image quality, that is, completely eliminates the combing effect on the edges of objects moving horizontally, as well as the jitter of a still picture (for example , in pause mode). To work with progressive scan, the TV requires a more powerful and expensive processor, but support for this mode is mandatory for modern HDTV screens.

High definition television standards are developed by the European "Information and Communication Technology and Consumer Electronics Association" (EICTA). To facilitate the identification of models, this organization also published requirements for the technical parameters of devices capable of processing high-definition signals. Also, a special labeling was approved.

Models that meet the minimum HDTV requirements are labeled "HD-Ready", which literally means "HDTV Ready". That is, a TV with the "HD-Ready" sticker is necessarily equipped with:

A screen with a resolution of at least 1280x720 pixels;

At least one input capable of receiving HD signals in 720p and 1080i formats. It can be a YPbPr1 analog component input, or digital DVI or HDMI;

At least one digital DVI or HDMI input supporting HDCP content protection technology.

The most common resolution for HD-Ready TVs is 1366x768 pixels. Such models are forced to interpolate the 1080i signal, reducing its resolution.

The “Full HD” label is given to TVs capable of displaying 1080p images and must be equipped with at least one HDMI input to receive a high-definition signal. The screen of a modern Full HD TV always has a resolution of 1920x1080.

The screen of an HDTV TV is always widescreen, that is, it has an aspect ratio of 16: 9. This format covers up to 70% of the field of view of the human eye, which allows the viewer to immerse himself in the atmosphere of the film, which enhances the viewing experience.

Russian on-air analogue television broadcasting has a resolution of 720x576 pixels with an aspect ratio of 4: 3. Video from a standard DVD is usually played in 720x480 (16: 9) resolution. A logical question arises - will the new TV be able to receive a signal from "non-HDTV" sources, and how will this affect the image quality?

Yes, an HDTV is capable of receiving and displaying a standard definition signal. In this case, an image with an aspect ratio of 4: 3 can be displayed on a widescreen screen in two ways: with black stripes at the edges of the picture, or by cropping slightly at the top and bottom. Some TV models have a special processing unit that removes noise from the analog signal, increases the resolution using interpolation, applies digital anti-aliasing algorithms, thus improving the picture to HDTV standards. However, one should not expect "miracles" from such transformations. A high definition signal is required to obtain a high quality picture.

Unfortunately, there is no widespread high-definition television broadcasting in Russia. This requires the modernization of a large number of TV stations and the transition to fully digital TV broadcasting, which is planned for 2015. Therefore, at the moment, only Blu-Ray discs, satellite or cable TV, game consoles can serve as a source of high-definition signals. Nevertheless, in some regions of the country, digital broadcasting is already being launched, and cable TV networks are emerging and developing.

Matrix response time

The concept of "response time" was not applied to CRT televisions, since the duration of the afterglow of the phosphor was rather short. But with the advent of "matrix" screens, this parameter has become very important.

Matrix response time is the average time it takes for a screen matrix element to transition from one state to another. Excessive response times can result in “trails” of residual glow behind fast moving objects.

Typically the time taken for a pixel to go from white to black and then back again is measured. But some manufacturers measure the response time in the so-called "GtG" (English "Gray-to-Gray") scheme. The response time is expressed in milliseconds (ms). Its typical values, for example for LCD matrices, are in the range from 2 to 10 ms.

When watching dynamic scenes in movies, for example, chases or battles, the fast response time will not allow the picture to "blur". For comfortable viewing of films and programs, a screen with a response time of up to 8-10 ms is enough, but if you plan to connect a TV to a computer, you should limit your choice to models with a response time of less than 5 ms. The response time can be ignored if you buy plasma. In this case, its value is invariably low.

Contrast

Another characteristic of a TV screen that affects viewing comfort is picture contrast, which is the ratio of the brightness of the lightest to the darkest part. That is, the brighter the matrix displays white, and the deeper, richer - black, the higher the contrast level of the screen. So, for example, at a contrast ratio of 1000: 1, the white areas are 1000 times brighter than the black ones. High contrast allows you to see more shades of color and picture detail.

But the intrinsic, "constructional" (also called static) contrast of even expensive LCD matrices is still insufficient, especially when playing HD video, where the requirements for image quality are very high.

To increase the visible contrast, manufacturers have come up with a fairly effective and, at the same time, inexpensive solution. Modern TV analyzes the content of each frame and automatically adjusts the screen brightness. Thus, in low-light scenes, the backlight emits less light, making dark colors deeper, and in bright frames, it gets brighter, emphasizing the white.

Contrast measured using this automatic backlight dimming is called Dynamic Contrast (DC). Its values ​​in expensive models can reach 5,000,000: 1, and an acceptable image quality is provided by dynamic contrast ratios of about 10,000: 1.

The use of LED backlighting for LCD TVs has significantly increased the contrast, so the image on the LED TV screen looks deeper and clearer than on a conventional LCD.

Brightness

The high brightness of the screen allows you to comfortably watch TV in external, natural or artificial lighting conditions. Low brightness images are difficult to read and cause excessive eye strain.

The brightness of a TV screen is expressed in luminous intensity per unit area and is measured in cd / m2 (read as "candela per square meter").

Currently, the most expensive models of LCD TVs are almost equal in brightness to plasma TVs, which have always won in this parameter due to the self-luminescence of the screen elements. But most of the LCD matrices are still inferior to them, since the flow of light from lamps or LEDs has to overcome a layer of liquid crystals, the transparency of which is not absolute. Typical brightness values ​​for LCD and LED TVs range from 300 to 600 cd / m2, while for "plasmas" it easily reaches 1500 cd / m2.

However, brightness is not the only important characteristic of a TV, as some manufacturers try to teach it. The fact is that with an increase in the brightness of the image, its contrast decreases, and the colors become dull and inconspicuous, despite the declared "large color gamut". Therefore, high screen brightness should always be combined with sufficient contrast.

Based on practical experience, we can formulate several recommendations for choosing the optimal ratio of brightness and contrast. So, for a budget TV model with a brightness of 300 cd / m2, the contrast must be at least 1000: 1. In the middle segment, we recommend choosing a screen with a brightness of 400-500 cd / m2 with a contrast ratio of about 5000-10000: 1, and for the high-end class - from 600 cd / m2 to at least 20,000: 1.

An excess supply of brightness will not be superfluous, especially since it can always be adjusted within a fairly wide range. And of course, not every TV can "compete" in brightness with direct sunlight, so you should avoid installing it in front of windows.

Viewing angles

The maximum viewing angle is another characteristic of the TV, which appeared with the advent of digital screens. It denotes the maximum angle to the plane of the TV screen, when viewed from which the image is perceived without distortion.

To understand where the distortions come from, it is necessary to carefully study the structure of the screen matrix - this effect is due to its very structure.

The liquid crystal matrix is ​​a multi-layer surface and is a very thin structure. The pixels are optically isolated from each other by polarizing filters, and the lamps or backlight LEDs are located at a very small, but still non-zero distance from them. And therefore the light, passing through the cells, falls into a kind of "well", which limits the area of ​​its dispersion.

A wider viewing angle is provided by a thinner and therefore expensive matrix. Most LCD TVs have a viewing angle of 170 degrees, while flagship models range from 175-178 degrees.

Distortion appears as a change in screen colors and a drop in the apparent brightness and contrast of the image. As the viewing angle increases, the observer sees not a sharp drop in the quality of the picture, but its gradual deterioration. The best results are obtained when looking perpendicular to the screen, and distortion remains subtle in the range from about -60 to +60 degrees. Thus, the optimal viewing angle for the TV is about 120 degrees.

Budget models usually have viewing angles of about 160-170 degrees. But with the correct installation of such a model, viewing from the "wrong" angle will be impossible, and you simply will not be able to notice the distortion, while saving quite a lot. A good option would be, for example, installing such a TV near the end (short) wall of a not too large room. In order not to experience discomfort associated with an incorrectly selected viewing angle, you need to consider the location of the TV.

For plasma panels, the viewing angle problem is not so acute due to the peculiarities of this technology. The fact is that visible light is emitted by a layer of phosphor, which is much closer to the outer surface of the screen than lamps or backlight LEDs for LCD and LED screens. Therefore, almost all plasma TVs provide a maximum viewing angle of about 175-178 degrees.

Interfaces

The TV interfaces allow you to connect other devices to it: DVD and Blu-Ray players and video recorders, game consoles, digital cameras and camcorders, surround sound speakers, laptops and other attributes of the modern “digital home”.

The list of possible interfaces is wide enough:

Composite (AV). It was widespread in the era of CRT TVs, but the quality it offers does not meet today's requirements. Therefore, TVs are equipped with a composite input for compatibility with older devices. Usually presented in the form of three RCA ("tulip") connectors, one of which, as a rule, yellow, is used for video transmission, and the other two - for stereo sound transmission.

Component. An analog interface that implements the transmission of a video signal in the form of three image components. This eliminates the need to mix the signal in the source and then separate it in the receiver, which provides better picture quality compared to the composite input. However, it is inferior to digital connections, and TVs are equipped with component video and audio outputs for compatibility with older devices. Switching is carried out using RCA connectors ("tulip"). Does not transmit sound.

SCART. Combined multi-pin interface for analog transmission (input and output) of image and sound over a cable up to 15 meters long. It is the standard for devices intended for sale on the European market. In terms of the video signal transmission quality, it is at the level of the component interface, but some TV models also allow two-way exchange of digital commands via SCART, for example, the synchronization of the TV and VCR start-up. Compatible with composite and component interfaces using SCART-"tulip" adapters.

SCART-RGB. This designation is sometimes used to identify a SCART interface that supports RGB video transmission for better image quality.

S-Video. An analog connector used to output images to a TV from a computer, laptop, video recorder, digital camera and other devices. By choosing the appropriate adapter cable, for example, from S-Video to 4 "tulips" or from S-Video to SCART, you can connect a variety of image sources. Does not transmit sound.

D-Sub. A common standard analog video output used to connect computers to a TV. The signal transmitted via this interface is very sensitive to interference and electromagnetic interference, so the image quality depends on the quality of the cable used and its length, which can be up to 15 meters. D-Sub equipped TVs can usually be used as full-fledged computer monitors. Does not transmit sound.

DVI. Transmits a higher quality picture than D-Sub due to the use of a digital signal format and no double digital-to-analog conversion. A 4.5 meter DVI cable allows you to transfer images with a resolution of 1920x1200, and a 15 meter cable - up to 1280x1024 pixels. Does not transmit sound.

HDMI. a modern high-definition multimedia interface designed to transmit high-definition video (up to 2560x1440) and multi-channel audio over a single cable up to 5 meters long. It is compatible with DVI, but is mainly used for switching various household audio / video equipment; also, via HDMI, you can connect a computer equipped with this interface to a TV.

Mini-jack. The stereo jack used for audio output is often found on the front of the TV. In this case, it is intended to connect headphones.

Coaxial audio output (BNC). Digital interface for sound transmission. It features high signal quality and minimal interference. Used to transfer sound between the TV and a disc player or AV receiver, and to connect surround speakers.

Optical audio-out (Toslink). Digital interface for transmitting surround sound. Allows you to transmit a multichannel signal without interference, thanks to the use of an optical cable that is not susceptible to electrical interference. Used to transfer sound between the TV and a disc player or AV receiver, and to connect surround speakers.

USB. A computer connector that has become widespread in television technology. Used to read music and videos from flash drives. Usually located on the front of the TV, which allows you to quickly connect a USB flash drive for viewing. In the absence of digital TV broadcasts, the USB port can serve as a convenient HD source.

As a rule, any TV set is equipped with a wide range of various connectors, but only expensive models can boast all existing interfaces and, accordingly, versatility in connection.

When choosing a TV, you need to think in advance about what devices you plan to connect it to, and make sure that the TV model you choose has the appropriate interfaces. In the set of ports, it is better to include those that may be useful in the future.

Recently, it has become very popular to connect devices via HDMI. In addition to its high bandwidth, this interface is highly versatile and is therefore equipped with many components of a modern home media system. Preference should be given to TV models that have as many HDMI ports as possible.

Tuners

Despite the possibility of connecting many signal sources, receiving television programs remains an important task for the TV. Any TV has a built-in electronic unit that is responsible for receiving a terrestrial, satellite or cable TV signal, which is called a tuner (English "tuner", literally, "tuner").

A TV can be equipped with more than one tuner. Thus, two tuners allow using the “Picture-in-picture” (PIP) mode to display images from two TV channels at once. This can be useful, for example, if you are waiting for a show to start while watching news or music videos. Often the manufacturer indicates PIP support in the characteristics of a TV that has only one tuner. In this case, this function will only work when connecting additional signal sources other than the antenna: disc player, computer, camcorder, satellite receiver or others.

Tuners are of three types:
analog. So far, the most relevant type of tuner for the Russian buyer. Allows you to receive an analog TV signal from a conventional antenna or cable TV network;

digital. Able to receive a digital television broadcast signal. At the moment, it is practically not conducted anywhere in Russia, therefore, the presence of a digital tuner on the TV now can be considered only as a reserve for the future;

hybrid. Combines the capabilities of digital and analog tuners. There are a lot of TVs equipped with a hybrid tuner on the market today, and buying such a model can probably be considered the best option.

Sound

The built-in speaker system is present in almost any modern TV. When buying a TV screen for the living room, it usually means connecting a home theater system, but if the target room is a kitchen or bedroom, you can also look at the device's own audio capabilities to save space.

Inexpensive TVs can only reproduce monaural sound and use one or two speakers. More advanced ones are equipped with a built-in stereo system, in which the number of speakers can be from two to eight. Some Russian terrestrial TV channels broadcast with stereo sound in A2 / NICAM format, and for full reception of such broadcasts the tuner must also support this format.

The high power of the TV's built-in speaker system is important for generating sufficient sound power in large rooms. It is rational that TVs of small diagonals are equipped with acoustics with a power of 1-5 W, and large ones - 10-20 W or more. As a rule, the manufacturer selects it in such a way as to provide a comfortable sound when the TV is installed in a suitable room (see the subsection "Screen diagonal").

When choosing a TV for the living room, you should pay attention to the presence of a Dolby Digital processor in it. It will allow the TV to independently decode the signal for playing a multi-channel 5.1 sound track, and if there is a built-in amplifier, output it to an external speaker system. Otherwise, you will need to connect another device equipped with a Dolby Digital decoder to enjoy surround sound.

Additional functions

Many modern TVs have in their arsenal a set of additional features, with the help of which manufacturers expand the functionality of products. It is rather difficult to give any specific recommendations here: your choice, most likely, will depend on how necessary and convenient one or another function seems to you.

Some Philips TVs are equipped with the AmbiLight function, which uses additional multi-colored lamps on the cabinet to create backlighting in the room. Its color is chosen depending on the color prevailing in the scene: for example, if there is fire there, the backlight will be orange-red. This allows you to enhance the experience of watching the movie and achieve a more immersive atmosphere.

Panasonic Viera series TVs have a VIERALink function that allows you to easily combine multiple devices of this brand, such as a disc player, satellite and AV receiver into a single coordinated system and control it with just one remote control. The Sony BraviaSync technology used in the Bravia series TVs works in a similar way.

Below is a short list of other additional features found in many different brands of TVs:

off / on timer. Allows you to set the TV to turn on or off automatically at a specific time. For example, the screen in the kitchen will turn on when you are going to work;

24Hz (24p True Cinema). Films are initially shot at 24 frames per second. But when burning them to a regular DVD, the format requires 25 frames per second, which leads to a slight acceleration of the image when viewing. A TV that supports this feature is capable of restoring the original playback frame rate, provided the disc player also supports it;

program guide (EPG). Electronic program guide with description. More convenient than its paper and newspaper version, but support for this function exists only for digital terrestrial or cable TV broadcasting;

protection from children. Prevents children from turning on the TV when adults are away. It can also implement blocking of individual TV channels;

teletext. Allows you to receive additional information on the TV screen, if such an opportunity is provided by local television broadcasting;

automatic volume control. TV channels and disc recordings may vary in volume. This function automatically analyzes the volume of the sound source and adjusts it according to a user-selected level;

enter channel names. Allows easy identification of channels using custom labels;

list of favorite channels. You can add the channels that you would like to watch into it, without wasting time switching programs one by one;

freeze frame (Time Shift). Provides the ability to "stop time" by pause while watching a TV program. Naturally, its broadcast continues, but you will not miss anything, since the TV saves a video to its internal memory, which you can watch later.

Some TV models provide a choice of operating modes: standard, game, cinema and others. Switching to the appropriate mode allows you to automatically adjust the display settings so that they are optimal for the selected image type. For example, the game mode activates a special circuit to reduce the response time of the sensor and thereby eliminate the blur effect of fast-moving objects, which is very important for games.

We buy a TV

Guided by the recommendations given and carefully analyzing the parameters, you can easily choose the TV that is most suitable for you. We hope that with the help of our tips, you can create a modern, high-tech, well-functioning media system in your home that will make your stay at home more fun and enjoyable.

Which TV screen contrast is better, dynamic or static?

Buying an LCD TV in a store is not an easy task. You have to take into account a lot of various parameters, and the cost of a TV is far from the first of them. In addition to the diagonal, type and country of the manufacturer, it is recommended to pay attention to the indicated contrast values ​​of the picture displayed on the LCD TV screen. And if the image quality is extremely important for you, then pay attention to how contrasting the picture can be given by this or that model.

What is contrast?

What is LCD Contrast Ratio? We are talking about the ratio of the brightness of two points, one of which corresponds to the lightest, and the other to the darkest area. Simply put, by indicating the contrast of the TV image, the manufacturer shows how many times the lightest point on the screen is brighter than the darkest point on the screen that can be produced by an LCD TV screen. Of course, the exact contrast parameters cannot be determined by eye. To determine the contrast, the TV must pass a special test using high-precision instruments. This means that manufacturers who indicate certain contrast ratios have to take their word for it. Alternatively, you can read one of the reviews or reviews on various sites and forums. Here is laid out unbiased information from users who have tested this LCD TV model personally.

Contrast types

As we have already said, the contrast can be not only static, but also dynamic. Static contrast, also called natural contrast, will determine the capabilities of a particular LCD TV model. Well, dynamic contrast is achieved through the use of special technologies. Static contrast is taken from the brightness of an individual pixel viewed in a static (stationary) scene. That is, a still image is taken, in which the darkest and brightest points are selected, and then the accepted formula is used. Dynamic contrast is measured only after the contrast enhancement technology is applied to the picture. LCD TVs have the ability to adjust the contrast, focusing on the plot of the reproduced video sequence.

Benefits of static contrast

Of course, LCD TVs with high static contrast ratios are valued much higher than those with high dynamic contrast ratios. And this is fully justified. It is enough to display a picture with white text on a black screen. A TV that has high natural contrast will actually show white text and black backgrounds.

On a TV with dynamic contrast ratio, white letters on a black background will appear gray. From this we conclude that TVs with high natural contrast will show more real ordinary video, which is highly appreciated by lovers of high-quality images. For example, in daylight, a black car on the screen will be really black, and in an evening scene, you can easily distinguish bright street lights. Approximately such an image, in terms of contrast, can be observed in modern cinemas.

Perfect Contrast TVs

It is worth noting that in terms of contrast, the most realistic image was provided by CRT TV models. But today, when HDTV is in vogue, CRT TVs are no longer available. As a result, the “yellow leader's jersey” was transferred to LCOS home projectors with the highest natural contrast, among which the JVC D-ILA devices stand out. Next to them are Sony SXRD devices. And only after them modern plasma TVs demonstrate good contrast.

Local dimming

In recent years, manufacturers of LCD TVs have been able to implement certain technologies that have made it possible to achieve acceptable levels of contrast. Particularly impressive results were achieved through the use of LED backlighting with local dimming technology. Of course, each pixel cannot be regulated, control is carried out only by a group of LEDs, but the result is more than decent. Ideally, the backlight LEDs should be positioned across the entire screen. But manufacturers deliberately abandoned such models, since they were too expensive, inaccessible to a wide group of consumers. Modern LCD TVs use side lighting with LEDs at the top and bottom. Side lighting can also work with local dimming technology. Side-lit LCD TVs show impressive contrast when using local dimming.

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One of the most important characteristics of a TV when choosing is the value of the contrast of the image on the TV screen. If you choose a TV for picture quality, then be sure to pay attention to the contrast value for different models.

A-priory contrast is equal to the ratio of brightness at the lightest point on the screen to the brightness of the point where the darkest image is. In other words, divide the white level by the black level and get the contrast. Only here the values ​​of these levels can be obtained only with a special check of the TV using specialized devices. Therefore, an ordinary user has to believe either manufacturers or various reviews on sites where TVs are tested. Who to trust more and how contrast is checked, and let's talk further.

We said that contrast is one of the most important characteristics of a TV. Therefore, manufacturers try to maximize this value to improve sales. The manufacturer can measure the brightness of a pixel in the laboratory when a signal is applied that is never used in real conditions. Then measure the brightness of this pixel in the absence of a signal, which is impossible during normal viewing. The contrast value is then calculated. And the values ​​measured under such conditions are included in the product passport. Because of this, we see today that the contrast values ​​of many TVs are simply off scale. All this is possible because there are no binding rules in the world for measuring display contrast.

Share static (natural) and dynamic contrast... Natural contrast depends only on the capabilities of the display, and dynamic is obtained as a result of the use of additional technologies.

Static contrast is measured by the brightness of points in one scene (brightest and darkest). When measuring dynamic contrast, technologies are used to overestimate it. The TV itself, during video playback, adjusts the contrast depending on the scene that is currently shown on the screen. That is, the backlight in the LCD matrix is ​​regulated. When displaying a bright scene, the luminous flux from the backlight increases. And when the scene changes to dark (night, dark room, etc.), then the backlight begins to reduce its luminous flux. It turns out that in bright scenes, due to the increase in light from the backlight, the black level is poor, and in dark scenes, the black level is good, but the luminous flux will decrease. This is hard for us to notice because in bright scenes the backlit black appears to be completely black. And in dark scenes, the brightness of light objects seems to be sufficient. This is a feature of human vision.

This backlight control scheme increases contrast, although not as much as the manufacturers claim. Indeed, many TVs with dynamic contrast ratio outperform devices that do not have such an adjustment scheme in terms of image quality.

But displays with high natural contrast will still be appreciated higher. This can be demonstrated by displaying a picture with white text on a black background. On a high static contrast screen, the text will indeed be white and the background will be black. But the display with high dynamic contrast, if it shows a black background, the letters will already be gray. Therefore, when playing a normal video on a screen with increased natural contrast, the picture will be as close as possible to the real image. For example, against the background of the evening sky, there will be bright street lights. And against the background of the bright daytime sky, a black car will indeed be black. This is the image we see in cinemas.

As real as possible, in contrast, the image was on the screens of CRT TVs. But with the advent of the HDTV era, these receivers have given way to other devices in the market. Today, high natural contrast values ​​are achieved with LCOS home projectors. The first place among these devices is occupied by JVC devices with their version of D-ILA. Next up is Sony with SXRD technology. Plasma TVs can already be placed in third place.

LCD TV manufacturers have implemented several technologies in recent years to achieve the same level of contrast that is possible with other models. The best results in enhancing contrast are obtained by using LED backlighting with local dimming. At the same time, it is impossible to adjust the backlighting of each pixel and there is no control of each LED separately, but the result is still good. But manufacturers have abandoned the most efficient type of backlighting, when LEDs are located across the entire screen area. This production turned out to be expensive. Today, the so-called side lighting is mainly used. Here the LEDs are located at the top and bottom. Local dimming schemes have also been developed for side lighting. TVs with such backlighting show quite good results in terms of contrast ratio.

When choosing a TV in a store it is difficult to evaluate the quality of the contrast of the display... External bright lighting interferes, screens can have different coatings: anti-glare or glossy. The true value of the contrast is not always written in the passport, because the manufacturers measure it in laboratories and when applying special signals to the screen. Even after reading several reviews on the Internet, it is not always clear what the real value of contrast is. After all, everyone measures it in their own way.

There is several contrast measurement techniques... First, a black field is fed to the input and the brightness is measured, and then a white field is measured and the brightness is measured. The contrast is good, but in real viewing it will never be completely white or completely black. At the same time, when displaying a normal video signal on the TV, video processing is turned on, which also makes its own changes. More truthful readings are given by the ANSI test, when a checkerboard with white and black fields is presented to the screen. This is more in line with the normal image. However, the white fields will affect the measurement of the brightness value of the black fields. So there is no single correct method for measuring contrast.

So the recommendations for choosing a TV with good contrast remain the same. If you will be watching mostly movies in a shaded room, plasma is best. In a lit room, LCD TV with LED backlighting will show good results due to its high brightness. Between these models, you can put an LCD TV if there is a margin for light output. And the main thing to remember is that any TV needs to be set up correctly. Adjust the brightness and contrast of the machine correctly to obtain the best picture quality.

Additionally:

PW Note: This article from ProjectorCentral covers the subject of contrast excellently. While at first glance it seems like there is a contradiction with my approach (I love the Full On / Off contrast setting), I would like to point out the following:

1. As a result, the author completely abandons independent measurements of ANSI contrast.
2. The author emphasizes the uselessness of the "full on / off contrast" parameter (hereinafter - Full On / Off Contrast) for an ordinary buyer, based on the data published by the manufacturer.
3. The author speaks a lot about the more expensive segment of home theater projectors.

Of all the published characteristics of projectors, the parameter " Full On / Off Contrast" least useful and more than others confusing... The claimed contrast ratio will not provide much useful information about what you will actually see on the screen and will certainly not provide any useful information as to how the two projectors will look when compared side-by-side.

And yet, since buyers usually do not have the opportunity to look at the projector in action or compare with another model before buying, they are addicted to the contrast declared by the manufacturer for a completely understandable reason. Who doesn't want a high contrast projector? And manufacturers are well aware of such sensitivity of the buyer to the contrast parameter, and therefore are forced to inflate it to absurd values ​​in order to just stay in the game.

Why are contrast specifications so terrible

There are two common methods for measuring contrast - " Full On / Off" and " ANSI". The first type of measurement is easier to manipulate, gives confusing numbers, and is the most commonly used in the projector industry. ANSI measurements are difficult to manipulate and produce much lower contrast values, but they are much more informative. This method is rarely used. by manufacturers of projectors, excluding specific niches.Let's see the difference between these methods.

Parameter Full On / Off Contrast Ratio measures the ratio of the brightness of an all-white test image (100 IRE, “full on”) to the brightness of an all-black image (0 IRE, “full off”). A ratio of 10,000: 1 means that the meter has recorded that the brightness of white is 10,000 times greater than that of black.

In contrast measurement method " ANSI"no white (100 IRE) and black (0 IRE) fields are used. Instead, a checkerboard image is used, consisting of 16 rectangles - 8 black and 8 white. First, the brightness of all white cells is measured and the values ​​obtained are averaged. Then the same is done with the black cells The ratio of the average white value to the average black value is the ANSI contrast ratio.

When it comes to projectors, the Full On / Off and ANSI methods give completely different numbers, and the ANSI contrast ratio is always significantly lower (in fact, incomparably lower). The reason is that, although we usually get similar white luminance values ​​for an all-white test image (100 IRE) and for white squares on a checkerboard, the black luminance levels on black checkerboard squares used in the ANSI method will always be higher than on a completely black test image (0 IRE).

Actually, why is it so? First of all, there is always the possibility of light scattering inside the optical system of a projector when projecting anything other than a black screen. When the projector is displaying a completely black test pattern (0 IRE), there is simply no light to scatter inside the projector, degrading black levels. On the other hand, when projecting a checkerboard, the picture is 50% white, and a lot of light passes through the projector. A tiny amount of this light is reflected and re-reflected within the lens or optical path, ultimately affecting the black level on the projected checkerboard. In addition, any dust caught in the path of the projected light will cause it to scatter.

But the reader will ask: "How can miniscule light scattering have such a significant impact on the contrast ratio?" Maybe! For example, the meter shows that with “full on” white screen (100 IRE) we have 1000 units, and with “full off” black (0 IRE) we have 0.05 units. This will be a contrast ratio of 20,000: 1.

Switching to the "checkerboard", the brightness of the white cells is still 1000 units, but due to light scattering, we will get 0.5 units on a black screen instead of 0.05. In this case, the contrast before our eyes fell 10 times, to 2000: 1, due to a subtle, almost imperceptible to the human eye (except in very dark conditions) change in the black level. This change in black level will be offset by any amount of bounced light in the room. Looking at the test patterns, the difference in contrast between 20,000: 1 and 2,000: 1 doesn't look as huge as the numbers differ.

But the fact remains that even small changes in black levels have a significant impact on the contrast setting. Everyone was paying attention to this little red EXIT sign in the theaters. This single sign can easily produce enough light to halve the contrast on the screen compared to a completely dark room.

Automatic iris and the like ...

When it comes to manipulating the "Full On / Off" contrast levels, the behavior of the projector itself plays a huge role. Many models adjust their luminous flux to the average brightness level of each individual scene. They can do this by adjusting the power consumption of the lamp on the fly, opening and closing the iris, or turning off the laser. Thus, when projecting a dark scene, you can instantly reduce the luminous flux level to make black appear blacker. Then, when it comes time to display a bright image, the luminous flux is returned to its full power, resulting in a brighter, brighter image. For most projectors using these features, this adjustment of light output is so fast that the viewer is rarely able to notice it.

These dimming functions do work and are useful, and we are not saying they are bad. The point is that they confuse all the cards in the game of contrast. When the projector adjusts brightness in this way, the “Full On / Off” contrast level will be based on measuring the blackest black in a dark scene and comparing it to the brightness of white in a bright scene, where similar black and white levels would not be possible in a single frame. Some manufacturers call it " Dynamic"contrast instead of" Full On / Off "contrast to emphasize that the numbers are derived from the aforementioned real-time luminous flux adjustments.

This is where the ANSI method comes in handy. Since it assumes the use of one test image, 50% white and 50% black, it completely excludes from our calculations the ability of the projector to dynamically adjust the luminous flux, changing it from frame to frame. As a result, the ANSI contrast level will be significantly lower dynamic contrast ratio. In theory, this setting will give you a better idea of ​​what you can see in any given frame.

Of course, ANSI contrast won't show anything about the positive contribution of dynamic dimming, so you'd be right too if you argue with me and say that ANSI contrast doesn't tell the whole story either.

Accurate ANSI contrast measurement

Despite our best wishes, ProjectorCentral.com does not measure ANSI contrast during the review process. This is because accurate ANSI contrast measurement requires either a pitch-black room with completely black and non-reflective walls, carpets, ceilings, clothing, etc., or a black tunnel camera or tent specifically designed for this task. Why? Because the light from the white cells of the "checkerboard" is reflected from all objects in the room, illuminating the black cells, making the obtained contrast measurements obviously defective. The only type of contrast measurement, at least which we would be willing to publish, should be done in a specialized laboratory equipped with everything necessary to carry out such measurements.

How different are the numbers for each method?

In general, the “Dynamic” contrast level gives the highest values, “Full On / Off” with disabled luminous flux control will give lower levels, and “ANSI” will give very low contrast values ​​that the consumer is not used to seeing. How small? Well, in the home theater world, where high contrast is preferable to high lumen output, ANSI contrast ratios of 300: 1 would be average, 700: 1 would be very good, and 1000: 1 would be considered outstanding. But how many people would want to buy a home theater projector that has a claimed contrast ratio of 700: 1? In today's highly competitive marketplace with millions-to-one contrast levels, few are.

Christie Digital is one of the few manufacturers to publish all three types of contrast characteristics (Dynamic, Full On / Off, and ANSI). For example, for an installation projector Christie DHD600-G declared 4800:1 dynamic, 1200:1 Full On / Off contrast and 250:1 ANSI contrast ratio. As you can see, even in the world of installation projectors, these methods give completely different numbers. Christie can afford to publish this information as it sells to knowledgeable buyers through professional AV resellers, and in the AV business everyone knows the difference between these parameters and what they mean.

On the other hand, the average consumer has no idea about these differences in contrast measurement methods. Unsurprisingly, they want the highest numbers possible. As such, for a manufacturer whose projectors are sold to the general public, it would be like death to publish ANSI contrast - they do not publish. A projector with an extremely high Dynamic Contrast Ratio, such as 500,000: 1, can still have an ANSI contrast ratio of 800: 1. In addition, this ANSI level means brilliant image contrast, but the consumer will never know about it. A manufacturer will only release ANSI contrast ratios if there is a strong desire to leave the business.

What to do?

For starters, remember that while ANSI contrast can be technically difficult to measure accurately, it is very easy to see. The high ANSI contrast ratio is characterized by solid blacks, sparkling whites, good yet natural color saturation [sic], accurate and well-defined shadow detail, and depth and dimensionality. Low ANSI contrast will result in weaker black levels, lower color saturation, washed out shadow detail, and a flatter, two-dimensional image. When you look at the projector and think to yourself, “Wow! This is excellent contrast! " - then often you react precisely to high ANSI, and not Full On / Off contrast.

Second, when installing two projectors side-by-side, it is usually obvious which one is the most contrasting, without any measurements. The main criterion is comparison of images by their depth (apparent volume).

Third, unless proven otherwise, it should be assumed that there is NO direct relationship between "Dynamic" or "Full On / Off" contrast on the one hand and ANSI contrast on the other. Very high contrast "Full On / Off" doesn’t mean ANSI contrast is high too - it can be really high, but you don’t know about it. The projector can have a low Full On / Off contrast ratio while still delivering very high ANSI contrast for impressive images. Don't be surprised if comparing Projector A with a claimed 50,000: 1 contrast ratio with Projector B at 500,000: 1, you find that Projector A's image looks much more contrasty. This happens all the time.

In other words, the contrast characteristics of "Dynamic" and "Full On / Off" are downright misleading. They tell you almost nothing about what the average shot will look like. It would be incredibly useful if everyone published ANSI contrast, but the risk is too great for the manufacturer, simply because the buyer will misunderstand it. Unless the manufacturer suddenly decides to try his luck in a serious way and publish ANSI contrast in the specifications, do yourself a favor and just ignore the claimed contrast levels seen in specs today... The declared Full On / Off and Dynamic Contrast levels will tell you nothing about how the image will look, and they are completely impossible to use to compare projectors.