Confusing contrast types that are best ignored. Image Contrast

When choosing a monitor, you should approach it very responsibly. After all, it is he who serves as the main object of information transfer from the computer to the user. Definitely, no one would want a monitor with uneven backlighting, dead pixels, incorrect color reproduction and other shortcomings. This material will help explain some criteria that will help you understand what exactly you need from a monitor.

The choice of a good monitor is determined by the sum of such characteristics as: type used matrices, backlight uniformity, matrix resolution, contrast(including dynamic), brightness, aspect ratio, Screen size, communication ports And appearance. Also, those factors that negatively affect eye health will be mentioned.

To begin with, it is worth understanding how the color sensation occurs when looking at the monitor.

RGB (Red,Green,Blue) - the number of color gradations and varieties visible to the human eye, which can be composed of basic colors (red, green, blue). Also, these are all the primary colors that a person can see. Monitor pixels consist of red, green and blue pixels, which at a certain brightness intensity can form more complex colors. Therefore, the more advanced the monitor matrix, the more color gradations it can display, and the more possible gradations it has for each of the red, green and blue pixels. The accuracy of color display and the level of static contrast depend on the quality and type of matrix.

Liquid crystal matrices consist of quite a few layers and b O a larger number of liquid crystals, which can build more combinations, each turning at a different angle, or changing its position in a certain angle. This is why simpler matrices work faster. This happens due to the fact that to occupy the required position, you need to perform fewer actions and with less accuracy than more complex matrices.

Let's take everything in order.

Type of LCD matrix.

What type of matrix should I choose?

It all depends on the tasks assigned to the monitor, the price and your personal preferences.

Let's start with the simplest ones and end with the more complex ones.

(twistednematic) matrix.

Monitors with this matrix are the most common. First invented LCD monitors were based on technology TN. From 100 monitors in the world, approximately 90 have TN matrix. Are the cheapest and simple to produce and therefore the most widespread.

Capable of transmitting color 18 -and or 24 -x bit range ( 6 or 8 bits per channel RGB), which although is a good indicator in comparison with the first LCD monitors on TN, nowadays this is not enough for high-quality color rendition.

TN matrix monitors have the following advantages:

• High response speed.

• Low price.

• High level of brightness and the ability to use any backlight.
  

Faster matrix response time – has a positive effect on the picture in dynamic scenes of films and games, making the picture less blurry and more realistic, which improves the perception of what is happening on the screen. In addition, when the frame rate drops below a comfortable value, this is not felt as pronounced as on slower matrices. For slow matrices, the updated frame is superimposed on the next one. This causes blinking and a more obvious “slowdown” of the image on the screen.

Production TN matrices are cheap, so they have a more attractive final price than other matrices.

However, monitors with a TN matrix have the following disadvantages:

• Small viewing angles. Color distortions up to inversion when viewed from an acute angle. Especially pronounced when looking from bottom to top.
  

• Quite poor contrast level.

• Incorrect, inaccurate color rendering.

Based on TN monitors can be considered more environmentally friendly in comparison with monitors on other LCD matrices. They consume the least amount of electricity due to the use of low-power backlights.

Also, backlit monitors are becoming increasingly common. LED diodes, which are now equipped with most TN monitors. Significant advantages LED The backlight does not provide, except for lower power consumption and longer service life of the monitor backlight. But it's not suitable for everyone. Budget monitors are equipped with cheap low-frequency PWM, which allow backlight blinking, which has an adverse effect on the eyes.

Console TN+film, indicates that another layer has been added to this matrix, which allows you to slightly expand the viewing angles and make the black color “blacker”. This type of matrix with an additional layer has become a standard and is usually indicated simply in the characteristics TN.

(In Plane Switching) matrices.

This type of matrix was developed by companies NEC And Hitachi.

The main goal was to get rid of shortcomings TN matrices Later, this technology was replaced by S—IPS(Super-IPS). Monitors with this technology are produced Dell, LG, Philips, Nec, ViewSonic, ASUS And Samsung(PLS). The main purpose of these monitors is to work with graphics, photo processing and other tasks that require accurate color reproduction, contrast and compliance with standards. sRGB And Adobe RGB. They are mainly used in the areas of professional work with 2D/3D graphics, photo editors, pre-press specialists, but are also popular among those who simply want to please their eyes with a high-quality picture.

The main advantages of IPS matrices:

• World's best color rendering among TFT LCD panels.

• High viewing angles.

• Good level of static contrast and color accuracy.

These matrices (most) are able to reproduce color in 24 bit a (by 8 bit for each RGB channel) without ASCR. Of course not 32 bits like CRT monitors, but pretty close to ideal. Moreover, many IPS matrices ( P-IPS, some S-IPS), already know how to convey color 30 bits, however, they are much more expensive and are not intended for computer games.

The disadvantages of IPS include:

• Higher price.

• Typically larger in size and weight compared to TN matrix monitors. Greater energy consumption.

• Low pixel response speed, but better than *VA matrices.
  

• On these matrices, more often than on others there are such unpleasant moments as glow, « wet rag"and tall input-lag.

Monitors on IPS matrix have a high price due to the complexity of their production technology.

There are many varieties and names created by individual matrix manufacturers.

To avoid confusion, we will describe the most modern types of IPS matrices:

AS -IPS – improved version S—IPS matrix, in which the problem of poor contrast was partially eliminated.

H—IPS – the contrast has been further improved and the violet flare has been removed when looking at the monitor from the side. With its release in 2006 year, now I have practically replaced the monitors with S—IPS matrix. Might have like 6 bit, yes 8 And 10 bits per channel. From 16.7 million to 1 billion colors.

e—IPS – variety H-IPS, but a matrix that is cheaper to produce and provides standard for IPS color gamut in 24 bits(By 8 to RGB channel). The matrix is ​​specially highlighted, which makes it possible to use LED backlights and less powerful CCFL. Aimed at the middle and budget sector of the market. Suitable for almost any purpose.

P—IPS – the most advanced IPS matrix up 2011 years, continued development H-IPS(but essentially a marketing name from ASUS). Has a color gamut 30 bit(10 bits per channel RGB and is most likely achieved through 8 bits + FRC), better response speed compared to S-IPS, enhanced contrast levels and best-in-class viewing angles. Not recommended for use in games with low frame rates. The slowdowns become more pronounced and interfere with the response speed, which causes blinking and blurriness.

UH-IPS- comparable to e-IPS. Also highlighted for use with LED backlights. At the same time, the black color suffered a little.

S-IPS II- similar in parameters to UH-IPS.

PLS - variation IPS from Samsung. Unlike IPS, it is possible to place pixels more densely, but the contrast suffers (the pixel design is not very good for this). Contrast is not higher 600:1 - the lowest rate among LCD matrices Even TN matrices this indicator is higher. Matrices PLS can use any type of backlight. According to characteristics, they are more preferable than MVAPVA matrices.

AH-IPS (since 2011) — most preferred IPS technology. The maximum color gamut of AH-IPS for 2014 does not exceed 8 bit+FRC, which gives a total of 1.07 billion colors in the most advanced matrices. Technologies are used that make it possible to produce matrices with high resolutions. Best color reproduction in class (highly depends on the manufacturer and purpose of the matrix). A small breakthrough was also achieved in viewing angles, thanks to which AH-IPS matrices came almost on par with plasma panels. The light transmittance of the IPS matrix has been improved, which means maximum brightness, coupled with a reduced need for powerful backlighting, which has a beneficial effect on the energy consumption of the screen as a whole. Contrast has been improved compared to S-IPS. For gamers, and in general, you can add significantly improved response time, which is now almost comparable to .

(Multi-domainPatterned Vertical Alignment) matrices(*VA).

The technology was developed by the corporation Fujitsu.

Is a kind of compromise between TN And IPS matrices. Price of monitors for MVA/PVA It also varies between prices for TN and IPS matrices.

Advantages of VA matrices:

• High viewing angles.
  

• The highest contrast among TFT LCD matrices. This is achieved thanks to the pixel, which consists of two parts, each of which can be controlled separately.
  

• Deep black color.

Disadvantages of VA matrices:

• Quite high response time.
  

• Distortion of shades and a sharp decrease in contrast in dark areas of the picture when viewed perpendicularly to the monitor.

The fundamental difference between PVA And MVA No.

PVA- is a proprietary technology of the corporation Samsung. Actually it's on 90% is the same MVA, but with a changed arrangement of electrodes and crystals. Explicit advantages of PVA above MVA does not have.

If you are sparing money for a high-quality matrix on IPS technology, perhaps the best option for you would be a monitor on xVA matrices.

Or you can look away e-IPS matrix, which is very similar in characteristics to MVA/PVA. Although e-IPS still preferable, as it has a better response time and does not have problems with loss of contrast when viewed directly.

Which monitor matrix should I choose?

Depends on your requirements.

TN

TN is suitable for:

• Games
• Internet surfing
• Thrifty user
• Office programs
  

TN is not suitable for:

• Watching films(poor viewing angles + unclear blacks + poor color rendition)
• Working with color and photos
• Professional programs and pre-press preparation
  

IPS

IPS is suitable for:

• Watching films
• Professional programs and prepress preparation
  
• Working with color and photos
• Games(+-; only for E-IPS, S-IPS II, UH-IPS)
• Internet surfing
• Office programs
  

IPS is not suitable for:

• Games(for P-IPS, S-IPS)
  

*VA

PVA/MVA suitable for:

• Watching films
• Professional programs and pre-press preparation
• Working with color and photos
  
• Internet surfing
• Office programs
  

PVA/MVA is not suitable for:

• Games(response speed too slow)

Monitor resolution, diagonal and aspect ratio.

Undoubtedly, the higher the resolution, the clearer and smoother the picture. More fine details are visible and less pixels are visible. Everything gets smaller, but this is not always a problem. In almost any operating system, you can adjust the scale and size of all elements, from font size to the size of icons and drop-down menus.

It's another matter if you have vision problems or you don't want to adjust anything, it is not recommended to use a very small pixel. Optimal diagonal for FullHD (1920x1080) — 23 —24 inches. For 1920x1200 — 24 inches, for 1680x1050 — 22 inches, 2560x1440 — 27 inches. By maintaining these proportions, you should not have any problems with reading, viewing images and small interface controls.

The most popular and common aspect ratios are 4:3 , 16:10 , 16:9 .

4:3

Currently the aspect ratio is square ( 4:3 ) is being withdrawn from the market due to its inconvenience and lack of versatility. This format is not convenient primarily for watching films, since films are in a wide format 21.5/9 , which is as close as possible to 16:9 . When viewing, large black bars appear at the top and bottom, and the image becomes much smaller in size. Using 4:3 Visible vision in games is also reduced, preventing you from seeing more. In addition, the format is not natural for human viewing angles.

16:9

This format is convenient because it is more standardized for HD films, and even monitors of this format, often have a resolution FullHD (1920x1080) or HDready (1366x768).

This is convenient, because films can be viewed almost in full screen. The stripes still remain, since modern films have a standard 21.5/9 . Also, on such a monitor it is very convenient to work with documents in several windows or programs with complex interfaces.

16:10

This type of monitor is as practical as 16:9 monitors, but not as wide. Suitable for those who have not yet owned widescreen monitors, but it is intended for professionals. Professional monitors mostly have this format. Most professional programs are “tailored” specifically to the 16:10 format. It is wide enough to work with text, code, building 3D/2D graphics in several windows. In addition, such monitors are also convenient for gaming, watching movies, and doing office work, just like on 16:9 monitors. At the same time, they are more familiar to human viewing angles and can be taken as a compromise between 4:3 And 16:9 .

Brightness and Contrast.

High contrast needed in order to better display blacks, shades and halftones. This is important when working with a monitor during daylight hours, since low contrast has a detrimental effect on the image in the presence of any light source other than the monitor (although brightness has a greater effect here). A good indicator is static contrast - 1000:1 and higher. It is calculated by the ratio of maximum brightness (white) to minimum (black).

There is also a measurement system dynamic contrast.

Dynamic Contrast – this is an automatic adjustment of the monitor lamps to certain parameters that are currently displayed on the screen.

Let's say a dark scene appears in the film, the monitor lamps begin to burn brighter, which increases the contrast and visibility of the scene. However, this system does not work instantly, and often incorrectly due to the fact that the entire scene on the screen does not always have dark tones. If there are light areas, they will be overexposed. Good indicator at the moment 2012 year is an indicator 10000000:1

But don't pay any attention to dynamic contrast. It is very rare that it brings tangible benefits or even works adequately. Moreover, all these huge numbers do not show the real picture.

Why is the dynamic contrast ratio always significantly higher on a monitor with than on a monitor with?

Because LED The backlight can turn on and off instantly. The measurement starts with the backlight completely turned off, so the indicator will be huge, plus add here the high brightness of the LEDs and a white background as the end point. CCFL backlight required more than 1 second to turn on, so the measurement takes place with the backlight turned on in advance on a black background.

First of all, you should pay attention to static contrast, not dynamic. No matter how much you like such huge values ​​in the characteristics. It's just marketing ploy .

Monitor brightness – not the most important parameter. Moreover, this is a double-edged sword. Therefore, we can say briefly that a good indicator of brightness is 300 cd/m2.

Why is it a double-edged sword? - it will be said a little lower, in the part "Monitor and Vision".

Communication ports.

When choosing a monitor, you should not rely on the manufacturer at this point. The most common mistake is buying a monitor with an analog input and a screen resolution higher than 1680x1050. The problem is that this aging interface is not always capable of providing the required data transfer rate for resolutions higher than 1680x1050. Cloudiness and blurriness appear on the screen, which can spoil the impression of the monitor. *to put it mildly

There must be an or port on board the monitor. Availability DVI And D-Sub this is the standard for a modern monitor. It's nice to also have a port HDMI, sometimes it can be useful for viewing HD video receiver or external player. If there is, but no DVI- Everything is fine. DVI And HDMI compatible through an adapter.

Types of monitor backlights. Monitor and its impact on vision.

What can you recommend to make your eyes less tired from the monitor?

Backlight brightness– one of the most important factors that affects the fatigue of your eyes. To reduce fatigue, reduce the brightness to the minimum comfortable value.

There is another problem and it is inherent in monitors with . Namely, if you reduce the brightness, it may appear visible flicker , which has an even greater effect on eye fatigue than high brightness. This is due to the peculiarity of adjusting the backlight using. Budget monitors use cheaper, low-frequency PWM, which create flickering diodes. The rate of light attenuation in a diode is much higher than in lamps, which is why LED backlight it more noticeable. In such monitors, it is better to maintain a golden mean between the minimum brightness and the beginning of visible flickering of the LEDs.

If you have any problems with eye fatigue, then it’s better to look for a monitor with CCFL backlight, or LED monitor with support 120 Hz. IN 3D monitors, more high-frequency frequencies are used PWM regulators than on regular ones. This applies to both LED backlights and CCFL.

Also, to make your eyes less tired, you can set the monitor to more soft And warm tones. This will help you spend more time working on the computer and help your eyes to better “switch” to the real world.

Do not forget that the monitor must be strictly at eye level and stand steadily, without swaying from side to side.

Eat myth what's more high-quality matrices give less fatigue for eyes. This is not true, matrices in no way can not influence it. Fatigue is only affected by intensity And quality of implementation monitor backlight.

Conclusions.

Let us repeat once again the most important characteristics that you should pay attention to when choosing a monitor for yourself.

They are no longer a new product, but they are an important attribute of every computer. Let's try to briefly talk about the main features of modern LCD monitors in order to have a general idea of ​​what we are going to buy.

First, let's highlight the main characteristics that you should pay attention to when choosing a monitor. These characteristics are: diagonal, matrix resolution, matrix technology, matrix backlight technology, viewing angles and options for connecting the monitor to a computer and other devices.

Diagonal and resolution

Undoubtedly, screen size is a purely individual characteristic and everyone selects it depending on the tasks they set for the monitor. But the combination of diagonal and monitor resolution is worth stopping at.

Let us recall that the resolution of a matrix (monitor) is the ratio of the number of pixels in height and width. Modern monitors generally have a resolution of 1366x768 (HD Ready) and 1920x1080 (Full HD), but since the resolution also depends on the geometry of the monitor, it can also be 1600x900 or 1680x1050.

It is very important that a monitor of the same diagonal can have a resolution of 1366x768 and 1920x1080. The difference here is obvious - the number of pixels is strictly tied to the physical size of the matrix, which in turn means that the size of the pixel itself in monitors with a resolution of 1920x1080 is smaller than in monitors with a resolution of 1366x768. This means that more graphic information can fit on a monitor with a resolution of 1920x1080.

It's worth thinking about this if you plan to use the monitor to watch videos or television programs. We explain why: the diagonal is the same, the viewing distance is the same, the video file is the same (for example, a DVD movie) - different resolutions and image quality are also different. In “full screen” mode, the quality is higher on a monitor with a resolution of 1366x768, because the video file has the same resolution. If you imagine that a video file has a resolution of 800x600 pixels, then you can understand that the higher the monitor resolution, the more the picture is “stretched” and therefore the image quality drops. For comfortable viewing, you will have to acquire HD quality files.

Of course, monitors with Full HD resolution are a step forward, but if you are not ready for such changes or do not intend to watch video, HD Ready monitors are perfect, especially if you plan to use the monitor as a TV and watch over-the-air television.

Viewing angles, brightness and contrast of LCD monitors

In fact, there’s no point in stopping and thinking about these parameters. In modern monitors, there cannot be a viewing angle less than 170°, and hardly anyone is able to look at such an angle. This characteristic is a relic of the past.

Image contrast is a very important parameter, although there are no significant differences here. There is a concept of static contrast and dynamic (DC). Of course, static contrast is more important, but you should understand what dynamic contrast means.

We are talking about the type of image that changes - video, games. In any frame there are both light and dark moments and the human eye perceives them as a whole, that is, if most of the screen is light, then the black level in a few dark areas does not matter much, and vice versa. Therefore, automatically adjusting the backlight brightness depending on the image is a completely reasonable thing. It is this automatic adjustment that is dynamic contrast.

The numbers for dynamic contrast are obtained very simply: if the static contrast is 1000:1, and the monitor electronics allow you to change it by 3 times, then the dynamic contrast is within 3000:1. Dynamic contrast numbers always look larger and sometimes shocking, but it’s still worth looking towards the static value. The higher the better.

Not a single modern monitor has a static contrast ratio below 1000:1. If you are into video games, then you need not only high static but also dynamic contrast.

Brightness is a little easier. In the parameters of modern LCD monitors it is within the range of 200 - 350 cd/m². At night these numbers mean absolutely nothing, but during the day they matter a little. To work in bright areas or in a building with a sunny side, of course, it would be better to have more brightness.

Matrix technology

Let's briefly consider the main monitor matrix technologies, which are TN (TN+film), IPS and *VA. The last one has an asterisk because there are two similar, with minor differences, technologies - MVA and PVA. So, TN+film technology is the most common. The advantages are a short response time, which is very important in dynamic images of videos and video games (shooting games, racing games) and a low price. We can say that monitors based on TN matrices are universal monitors.

Monitors based on IPS matrix are much more expensive than TN monitors. The main disadvantages, if you do not take into account the price, are the higher response time and, as a common disadvantage of almost all LCD matrices, insufficient black blackness. But, compared to TN monitors, IPS provide more believable TrueColor and more realistic viewing angles. The picture looks noticeably better and more contrasty. Such monitors are more suitable for those who work with graphics, since their soft and accurate color reproduction is almost as good as that of CRT monitors. All professional monitors for working with graphics are made on an IPS matrix.

Monitors based on *VA matrices. Both viewing angles and color rendering *VA monitors are much better than TN ones, however, these parameters are inferior to IPS matrices. Response time is longer than TN monitors. Perhaps the main advantage of *VA monitors is the unprecedented contrast for LCD matrices, which gives almost real black color. Such monitors are better suited for those who work with text, black on white and vice versa, drawing graphics.

Matrix backlight technology

Today, the most advanced is LED lighting, based on the principle of LED glow. The service life of LED backlighting is 40% greater than that of conventional CCFL backlighting, which is slowly beginning to take its place in history.

We won't dwell too much on the details. The Imagine store recommends monitors with LED backlighting.

Connecting the monitor to a computer and other devices

Today, the main monitor connection interfaces are D-Sub (VGA), DVI and HDMI.

D-sub - analog interface. The presence of such a connector in a modern monitor can only be justified by connecting an older computer or other equipment to it. The video signal is transmitted in analog form, which does not exclude interference and other bad influences.

DVI - digital interface. This type of connection provides for the transmission of a digital signal, thanks to which the best image quality and color reproduction are achieved. If your computer's video card has such a connector, it is better to choose a monitor with a DVI interface.

And finally, the HDMI interface. Its fundamental difference from DVI is that in addition to digital video, multi-channel digital audio is also transmitted. HDMI and DVI interfaces use different types of connectors but identical coding systems, so they can be easily connected to each other using a simple adapter

That's all that can be highlighted in modern LCD monitors. We hope our advice will help you choose what you need.

Everyone knows very well that cameras are not perfect and do not always accurately match the color (light) in the photo. It happens that the flash does not have time to charge and we see an almost black square of Malevich, sometimes it works too much and we see a white square of an unknown artist with red dots in the middle (the eyes of a hamster), and sometimes we are trying not to depend on the flash, we try to shoot without it, and the photo turns out to be a yellowish-brownish cloudy shade. All this can be easily cured using Photoshop (of course, within reasonable limits! Of course, a completely black or completely overexposed frame cannot be restored).

How to change brightness, contrast and saturation correctly

Let's start first with brief and then brief definitions in order to understand what we are changing.

What dictionaries tell us on this topic:

Brightness- light characteristics of bodies. The ratio of the intensity of light emitted by a surface to the area of ​​its projection on a plane perpendicular to the axis of observation.

Contrast— distinguishability of the object of observation from the surrounding background (monochromatic radiation); color contrast is a type of optical contrast associated with the difference in color shades.

Saturation— in physical terms, color saturation is determined by the nature of the distribution of radiation in the spectrum of visible light.

Hmm... Indigestible terms... I’ll try to formulate it more simply and related to this topic:

Brightness- the amount of white in your photo. The higher you set the brightness, the brighter the frame becomes.

Contrast- the difference between different, adjacent colors. The higher the contrast, the more sharply we see the transition from one color to another (sometimes contrast works as sharpening).

Saturation- how juicy and bright this or that color looks. You can enlarge it within immodest limits - then the photo even begins to “hurt” the eye.

You can, of course, describe each of these characteristics point by point, but this would be wrong. It is correct to change all three frame settings in a comprehensive manner. How? Now let's figure it out...

Let’s take this dark, low-contrast photo for consideration...

These commands are hidden in the “Image” menu, then “Correction”, then “Brightness / Contrast” and “Hue / Saturation”:

And

When we press the “Brightness / Contrast” button we see a window like this:

When choosing “Background Color / Saturation” this is what it looks like:

First, open “Brightness / Contrast” and calmly and peacefully move both sliders to the right to the required brightness and contrast values ​​(all this is done in a purely intuitive way and in each case in its own way!). You should not always set exactly the same values ​​as in this frame:

It seemed to me that first you need to set the brightness to +120 and the contrast to +30. But everyone notices that the colors are too bright and unnatural. It’s good that we know where the “Background Color / Saturation” menu is located, which will help us fix this:

It seems to me that if you reset the saturation value by 13 points it turns out quite well. That seems to be all, but I always play it safe and go into “Brightness / Contrast” one more time, checking if something else needs to be changed to achieve the most beautiful result and realistic photo.

(CRT) completely disappeared from the shelves of computer stores, giving way to their liquid crystal counterparts. People unfamiliar with this technology often get confused about the terms, since there are several names for the same item. To avoid misunderstandings, let's immediately clarify this issue: LCD, LCD - all these are the same liquid crystal technology, and not different. LCD stands for Liquid Crystal Display. Indirectly, the term “TFT” can be attributed here, meaning the use of thin-film transistors to control the matrix. Since they are not used in CRTs, it is obvious that the mention of TFT indicates LCD.

Having replaced old CRT monitors with modern LCDs, many owners were faced with an amazing phenomenon - in the first time after the transition, their eyes began to hurt, and for some, even Hence the subsequent question - “how is it done for the eyes.” There are many recommendations on the Internet, but most of them are incomplete, because the very reason for what is happening is cleverly overlooked. Indeed, if monitor contrast and brightness in LCD and CRT technologies are similar concepts, then where does the discomfort in the eyes come from when working with LCD? After all, this shouldn’t happen. The real reason for eye fatigue is that the operating principle of the backlight is based on gas discharges in the tube, and even modern LED backlights also have flickering (read about PWM control of LEDs). In addition, the color of the glow, both the lamp and the diodes, is unnatural; it has a defective spectrum. It’s invisible to the eye, but you can’t fool the visual receptors.

In general, monitor contrast is a numerical value that represents the ratio of the brightness differences between the lightest white point and the darkest black point. In monitors it is indicated in the form “xxx:y”. In fact, it's a different way of writing. For example, the contrast of a monitor with a maximum point brightness of 300 cd/m2 and a minimum of 0.5 cd/m2 will be (300-0.5)/0.5 = 599:1. It is generally accepted that the higher the contrast value, the clearer the picture. This is partly true, but only to a certain limit, since an infinite increase leads to image distortion (light details on a white background cease to be distinguishable). If the monitor contrast is not adjusted properly, then this is one of the reasons for the feeling of sand in the eyes when changing from CRT to LCD.

Note that all methods of setting parameters offered on the Internet are subjective. Each user must make adjustments based solely on personal preferences. In the Windows 7 operating system, there is a built-in monitor brightness setting that allows you to optimally set the brightness values, as well as contrast and gamma.

On the desktop, right-click, go to “Screen Resolution”, then “Make text and other elements larger or smaller” and “Color calibration”. By clicking “Next”, we follow the wizard’s advice (there is also detailed help here). At the end, you will be asked to configure the display of fonts using Clear Type technology: in the samples we indicate the clearest and “boldest” lines of letters.

Additionally, you can configure the monitor itself. To do this, set the contrast to 20-40%, and achieve a high-quality image with brightness. In some cases, the brightness may be zero, which is quite acceptable. The color temperature (deviation into the yellow or blue spectrum) must be set based on the yellow tint corresponding to the color temperature of sunlight (6300 K). Various image enhancement mechanisms and dynamic contrast do not allow you to correctly configure the monitor, so you need to compare the enhanced and natural operating modes and choose the best one for yourself.

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

A-priory contrast equals brightness ratio at the lightest point of the screen to the brightness of the point where the image is darkest. In other words, we divide the white level by the black level and get contrast. Only the values ​​of these levels can only be obtained through a special test of the TV using specialized instruments. Therefore, the average user has to trust either the manufacturers or various reviews on sites where TVs are tested. Who to trust more and how to check the contrast, and we’ll 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 applying a signal 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. After this, the contrast value is 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 the charts. All this is possible because there are no mandatory rules in the world for measuring the contrast of displays.

Separate static (natural) and dynamic contrast. Natural contrast depends only on the capabilities of the display, while dynamic contrast 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 increase it. When playing a video, the TV itself adjusts the contrast depending on the scene currently shown on the screen. That is, the backlight in the LCD matrix is ​​adjusted. When showing 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 on bright scenes, due to the increase in light from the backlight, the black level is poor, and on dark scenes, the black level is good, but the luminous flux will decrease. This is hard for us to notice because in bright scenes even backlit black appears completely black. And in dark scenes, the brightness of light objects seems sufficient. This is a feature of human vision.

This backlight control scheme increases contrast, although not as much as the manufacturers claim. And indeed, many TVs with dynamic contrast have superior image quality to devices that do not have such an adjustment scheme.

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

As real as possible, in terms of contrast, the image was on CRT TV screens. But with the advent of the HDTV era, these television receivers gave up their place in the market to other devices. Today, high natural contrast values ​​are achieved using LCOS home projectors. The first place among these devices is occupied by JVC devices with their version of D-ILA. Next we can mention Sony with SXRD technology. In third place you can already put plasma TVs.

LCD TV manufacturers have introduced several technologies in recent years to achieve the level of contrast that is possible in other models. The best results in increasing contrast are achieved by using LED backlighting with local dimming. In this case, it is impossible to adjust the backlight of each pixel and each LED is not controlled individually, but the result is still good. But manufacturers have abandoned the most effective type of backlight, when LEDs are located over the entire screen area. Such production turned out to be expensive. Today, 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 fairly good results in terms of contrast.

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

Eat several contrast measurement techniques. First, a black field is fed to the input and the brightness is measured, and then a white field is applied and the brightness is measured. The result is good contrast, but during actual viewing there will never be a completely white or completely black picture. At the same time, when displaying a regular video signal on the TV, video processing is turned on, which also makes its own changes. More accurate readings are given by the ANSI test, when a checkerboard field with white and black fields is shown on the screen. This is more consistent with the normal image. But in this case, 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'll mostly be watching movies in a darkened room, then plasma is your best bet. In a lit room, an LCD TV with LED backlight will show good results due to its high brightness. Between these models you can put an LCD TV if there is a reserve in light output. And the main thing you need to remember is that any TV needs to be properly configured. Adjust the brightness and contrast of the device correctly to obtain the highest quality image.

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