Disadvantages of curved TVs. Curved (concave) TV (monitor) screen: advantages and disadvantages

The situation with propaganda curved TVs somewhat reminds me of the 3D “revolution”, when only the laziest manufacturer did not focus on supporting this technology in their devices. Fortunately, today the hype around glasses-based 3D has died down. And manufacturers remember the presence of this function as the last thing. If they remember at all. And all because it’s 2015. Nowadays 4K (Ultra HD) and curved screens rule the roost. In the first case, it is unlikely that you will be able to find fault with the content generator and the manufacturers of the corresponding equipment. A new format is overdue, and it’s good. Technology allows us to begin the 4K era now. The only thing left to do is to create lots and lots of high-quality content. True, there is no revolution in Ultra HD - pure evolution! In the same way, at one time HD resolution was replaced by Full HD. But imposing devices with curved screen raises many questions and disputes. I will try to answer some of them in this note.

Pros and cons of curved TVs

In general, it is incorrect to call a curved TV curved. All because of the notorious literal translation of the foreign expression curved. All belonging to this class modern models- concave! Surely many readers have seen an era when in the living room there was a huge TV with a cathode ray tube, the convex surface of which played the role of a screen. Since then, the word “box” has been attached to it, which is applicable even now, even for models that are not inferior in body thickness to modern smartphones. It’s a paradox, but when the first flat-panel TVs began to appear on sale, marketers also did not sleep, assuring that this was real super quality!

Curved screens are also used in cinemas. But in these entertainment venues they serve a specific role. Firstly, as you know, the lens of a film projector is almost a point source of the image. The beam of light from it is much better projected onto a concave screen, but not onto a flat one. Otherwise, so-called pincushion distortion may occur at the edges of the picture. Secondly, a curved screen in a cinema expands the field of view, because in proportion the distance from it to the viewer is very small.

Marketers did not hesitate to take advantage of this fact, starting to compare curved TV, installed at home, with a cinema screen. “IMAX in your living room” - you’ve been to IMAX, haven’t you? Did you feel such a fascinating involvement in what was happening? It’s as if all the events of the film take place directly with your participation. Get the same experience at home with a curved TV...

This is where we get to the first myth associated with this type of device.

More immersion

In fact, a curved TV screen can actually, to use a marketing phrase, provide greater immersion to the user. Only this should be very big TV. After all, in the same IMAX a giant canvas is used, figuratively “enveloping” the cinephile. The fact is that with a diagonal of about 55’’ you won’t feel this. In this case, you need to sit very close to the TV. But this doesn't always work out.

So, in the first part of the guide to choosing a TV, I described the recommendations of THX, a reputable “player” in the film and television industry. According to them, to achieve “greater immersion,” a person should sit at such a distance that the screen covers 40% of your field of view. For 55 inches this parameter will be 1.7 meters. However, this dependence also includes another parameter - screen resolution. For HD, the distance increases to 3.23 meters, and for Full HD - 2.18 meters. Therefore, we will need a TV with Ultra HD resolution. And here I have to write a couple of sentences about the fact that there is not so much content for 4K.

Horopteric line

There is one more point. LG at one time introduced such a concept as a “horopter line”, which determines the equidistance of points on the screen for both eyes of viewers. That is, it is an arc in the center of which the user is located. If the surface of the TV screen is located at a distance corresponding to the horopter line, then your eyes will not have to adjust focus when viewing the screen. So, adhering to this theory (in fact, there are two of them: theoretical and empirical), for example, the LG 55EC930V TV must be viewed from a distance of 5 meters. This is a very long distance. Therefore, we can draw the following conclusion: the radius of curvature of the LG 55EC930V screen is not optimal for 55 inches. It feels very good to the eye. At a distance of two meters and further, the LG 55EC930V simply seems flat. And in the review, I focused the attention of readers on this, also arguing that in most cases, curvature is simply a design move. To really increase the effect of involvement in what is happening while watching a movie, for such a radius of curvature you will need a model with a diagonal of 100+ inches. These TVs are sold, but you can't afford them.

Increased contrast and viewing angles

Let's move on. Another argument in favor of buying a concave TV is the assumptions about increasing viewing angles and contrast. Again, returning to the LG 55EC930V model, that is, to OLED, we can safely say that everything is in order with these parameters. Yes, if only because this is OLED - a technology that has ideal viewing angles (each OLED pixel emits light in all directions evenly, which is why the image at different angles does not change at all) and absolutely zero black color. What about curved LCDs?

In theory, a concave screen can compensate for the loss of contrast on the sides. This is most noticeable if you sit very close to the TV. It’s better in front of a large monitor, because in this case the distance from the eyes to the monitor will be approximately 40-50 cm. With a size of 27 inches and above, the effect of concavity will be positive. It is important to understand that in most cases there is only one person sitting in front of the monitor screen.

However, it is not always possible to watch TV alone. If the family is large, then, as a rule, a sofa a couple of meters wide will be completely occupied. And this means that only one person will sit in the correct position. Others will look at the concave screen from different angles. Thus, the width of the 55-inch model is only 120 cm. Flat-panel TVs also have this problem. But we are identifying precisely the advantages and disadvantages of concave devices.

Let's say I'm sitting to the left of the center of the screen. In this case, when shifted, the angle relative to the right edge will become increasingly sharper, and relative to the left edge - increasingly blunter. And vice versa. All this causes one side of the curved screen to become almost parallel to the line of sight. And this is uncomfortable and inconvenient.

Changing the viewing angle depending on where the viewer sits

The image below shows the area comfortable viewing for concave TVs. See how narrow it is. And in most cases, it will be problematic to accommodate even three users in the green sector. In the case of the LG 55EC930V, even two. Here we again return to the issue of sitting as close to the TV as possible.

Of course, the above picture is not a strict rule that you will certainly have to follow. Just leaving the comfortable viewing area, all the advantages of the concavity of the display disappear.

Comfortable viewing area for concave TVs

Reducing reflections

The curved surface of the screen changes the angle of reflection of light rays. Glare is reduced. Thus, concavity sets the focal point at a distance of half the radius of curvature from the center of the screen. If a person sits further than this focal point, the reflections become blurred.

Measuring the Focal Point for a Concave Screen

The effect of visual enlargement of the screen on Samsung TVs

And this is how LG did it. Pay attention to the proportions in the picture. If they are true, then the person depicted is sitting in front of the TV at a distance of a meter. Maybe one and a half.

The effect of visual enlargement of the screen on LG TVs

Televisions have long become almost the main device in any home. Consumers practically never ask the question: does it make sense to buy this technical item at all? But what really worries many is the question: which TV is better - curved or straight?

When it comes to choosing a new TV, people, as a rule, do not fully understand what they want to buy, and even more difficult to explain their preferences to others. The vast majority of modern televisions have flat screens, and conventional picture tube units remain in the minority.

Without understanding the main characteristics, it is impossible to evaluate the device and make the right decision. For curved and straight TVs, the indicators will be different, but both devices should be considered through the prism of the following defining parameters:

Brightness. Today, all televisions are produced with sufficient indicators of this characteristic. In addition, it can be adjusted in all devices.
Permission. This value determines the ratio of the number of matrix elements per unit area horizontally and vertically. The higher the pixel element count, the better the image quality. Perfect quality pictures on the screen are obtained only if this value completely matches the video signal and the monitor.
Contrast. This characteristic indicates the difference in brightness in different areas of the screen, based on the brightest and darkest. It is divided into static and dynamic differences in the characteristics of different parts of the image.
Viewing angle. This is an indicator of the maximum angle to the screen plane at which the image is not distorted. Indicators are considered normal - 175-178 degrees vertically and horizontally.
Response time. This is the time the pixel's state changes. The shorter this time, the clearer the picture will be and the less blurriness will be noticeable.
Connectivity. The TV must have a sufficient number of connectors and their location must be convenient so that the consumer can connect to the device everything that he would not want (camera, flash drive, headphones, antenna, home cinema, satellite receiver and more).
Screen diagonal. This parameter is measured in inches. You need to choose the diagonal based on the distance at which viewing will take place. The optimal distance should be equal to 3-4 screen diagonals.

Of the above, more attention should be paid to resolution first.

Features of curved TVs

The idea of concave monitors is far from a modern technology. They have been used for quite a long time in large format for showing films in theaters and are designed to solve the following problems:

This type of screen transmits the image from the projector more correctly.
It increases the radius of perception for viewers who are sitting close enough.
Allows you to immerse yourself in what is happening, since a person is located, as it were, under a dome.

On a large canvas this is, of course, obvious. But characteristic features inherent in not very large home curved TVs.

Deep Dive

To feel big difference In this question between a straight and curved TV, it is necessary that the second one has at least a diagonal of 55 inches, and the viewer is at a distance of 1.7 m from it. With such a diagonal, a curved plane will cover a larger area of the field of view. And this can deeply immerse you in the atmosphere of what is happening on the screen.

In addition, curved TV panels have another clear advantage - high-resolution 4K Ultra HD compatibility. This innovative solution will certainly show itself in the future, so such devices “for growth” are very promising.

Contrast and viewing angles

A concave screen can compensate for the decrease in contrast in the side parts of the monitor if a person sits very close to the device. A higher format improves the quality of the viewer's experience in terms of contrast and smoothing of corners on the sides.

If the whole company watches TV. And only one user has the opportunity to sit in the best central place, various experiments show that there are quite a few comfortable viewing points in the case of both straight and concave screens. If a person leaves the comfortable viewing area, then all the stated advantages of a concave display simply disappear.

Optical distortion

This is very controversial issue. The matrix sensors responsible for focusing the video camera are located throughout the entire plane, therefore, the video captured by them is initially positioned for viewing on a flat surface. And if a curved surface is used for display, then the director’s original idea will simply be distorted. In this matter, concave models will clearly lose to straight ones. And based on this indicator, it does not seem that the screen of a curved TV is better.

Reducing reflections

Rays of light constantly fall on the monitor from third party sources. And with the curvature of the screen plane, the angle of refraction of these rays changes, which makes it possible to reduce glare on the screen. This is clearly noticeable in rooms with bright light. And the further the user sits from the screen, the more the intensity of the glow of foreign objects in the monitor will decrease.

Visual increase

This concept really does exist. The screen may appear larger than it actually is, but again it all depends on the distance at which the consumer is from the monitor. The further the viewer moves away from the screen, the increased visual perception of width will decrease. So this advantage is also quite relative.

Advantages and Disadvantages

When thinking about which TV is better - curved or straight, you should pay attention to the following advantages of concave screens compared to flat LCDs:

good glare reflection;
increased visual perception of the screen;
one user, occupying a comfortable zone, can receive expanded viewing angles and improved contrast.

But the following disadvantages cannot be ignored:

when viewing in a group, viewing angles and contrast ratios deteriorate for those sitting outside their comfort zone;
the TV becomes more bulky due to its overall thickness;
The curvature effect cannot be disabled;
it is not always possible to fit organically into the interior;
high cost.

If you don’t succumb to the influence of marketers, but weigh everything wisely, it turns out that modern televisions with concave screens seemed to have degraded. So, we can say, if we evaluate them by overall quality images from the perspective of most of the general home audience. For classic families, a concave screen is a failure.

Such models are perfect for exhibitions and shows, but for ordinary people in the question of a curved or flat TV, it is still better to give preference to flat ones. Direct screens also have their flaws, but they are as close as possible for use by a wide home audience.

Audio and video equipment manufacturers regularly announce the introduction of new technologies that improve the performance of their products. Unfortunately, not every know-how, not to mention significant benefit from the point of view of using the equipment. Nevertheless, achievements that change the mass consumer’s understanding of the properties of multimedia equipment appear, and, as a rule, their announcements are accompanied by lavish advertising. Three years ago, it was in this style that a curved TV screen appeared on the market, the advantages of which were actively replicated by marketers from LG, Sony and Samsung. By the way, even today, when a whole segment of models with a non-standard display has formed, the list of manufacturers participating in it is not so wide. And the more attractive the available offers.

with concave screen

Before moving on to considering the pros and cons of an innovative solution, it is worthwhile to take a closer look at its features. The main difference is the changed radius of the television panel - in other words, the shape of the screen, which is concave in the direction opposite to the viewer's position. However, it cannot be said that this principle of presenting a “picture” is truly revolutionary. It is, in particular, used in the design of theater stages and movie screens. And it is quite logical that correcting the shape of the projector display ultimately made it possible to implement a curved TV screen. Advantages and Disadvantages this decision still not so clear. If in a cinema the effect of a concave screen is obvious due to its large size, then in the case of television displays the advantages are found only in the case of a large diagonal. There are other nuances of such models, familiarity with which will allow you to form a more complete opinion about the new technology.

Deep Dive

The curved plane allows you to cover a large area of the field of view, so it may well create a feeling of deep immersion in the atmosphere of the film. For example, a flat screen with similar dimensions due to its shape will not be able to provide the same coverage. However, users note the minimal increase in visibility provided by the curved TV screen. The advantages in this indicator are most clearly manifested only in the case of large displays- at least 55 inches. However, a flat screen with this format can provide good film penetration. There is another trump card on the side of concave TV panels - this is high-resolution fusion in the 4K UltraHD format. Thanks to this technology, a truly non-standard image has the advantage of wider coverage.

Contrast and viewing angles

In this case, it is worth noting OLED technology, the carriers of which are currently TVs with concave screens. The advantages of this combination are expressed in two factors - increased sharpness and contrast, as well as expanded viewing angles. Actually, these are related design features, which in practice give the effect of the integrity of the “picture” and the feeling of a larger screen area without the usual angularity characteristic of traditional models.

According to the manufacturers themselves, a concave screen can increase contrast in the side areas. This will be especially evident in the perception of a viewer sitting close to the concave panel. It’s even better to use a large monitor for this purpose, since the distance to it will be even less - about 45 cm. This advantage A curved TV screen can also be observed in models with a diagonal of 27 inches. Further, the larger the format, the higher the quality of visual perception in terms of contrast and smoothing of side angles.

Visual increase in screen area

Under certain conditions, the curved shape of the screen can actually create the feeling that the TV has a larger area than a flat model with the same diagonal. However, it is possible to achieve a significant disclosure of this factor only if the viewer is located at the optimal point in relation to the place where the curved TV screen is located. The benefits of increasing the perceptual area of the “picture” are the most effective tool for marketers. At the same time, it cannot be said that this is a fiction and a spinning myth. If positioned correctly, the viewer will feel the difference, but it will only be noticeable if a large screen is used.

The need to be in the center of the screen

This is not a requirement at all, but in order to fully experience not just the advantages, but the peculiarities of eye contact with the concave screen, you need to be positioned strictly in the center of the TV. In this case, you will notice the absence of distortion and glare, as well as the visual expansion of viewing angles that characterize a curved TV screen. The advantages in this case can only be considered conditionally, since they are achieved only during a viewing session alone. Most of the advantages of a concave screen are not revealed in any way to viewers who look at the display at an angle - that is, sitting at the edges of the sofa.

High cost

It's not surprising that new development costs more than its less technologically advanced counterparts. However, experts have not yet observed any prerequisites for reducing the cost of such models, which is also natural on the market household appliances. Today, models with a diagonal of 40-55 inches can be purchased for an average of 70-100 thousand rubles. And this is not the limit, since all the accompanying technological additions in the spirit of the mentioned 4K format increase the price tags for which TVs with curved screens are sold by several tens of thousands. Are they needed for that kind of money? The answer in each case will be individual, but models with a flat screen for the same 100 thousand rubles. They also offer many opportunities for a pleasant movie show. And this applies not only to the large one, which can be 70-80 inches. The traditional form factor continues to expand into more familiar areas, including interactive and communication capabilities.

Does it make sense to buy a TV with a curved screen?

The bend of the television panel, despite all the efforts of marketers to fill its existence with meaning, in essence, does not yet give the viewer anything fundamentally new. For example, image quality in the most advanced versions in to a greater extent increases high resolution UltraHD rather than concave design. As for increasing the viewing area of the “picture,” the increase will be insignificant, and you will have to overpay several thousand for it, and that’s at a minimum. In that case, why not just buy regular model with a larger diagonal, which will certainly expand the area of visual perception. Considering all of the above, you might wonder why curved TVs are needed? First of all, we cannot discount the desire of manufacturers to make money on a new fashion. But if you look at such a model from a consumer’s point of view, it may well compete with large-format flat screens for home theaters. Although in this context, prices for concave models do not correspond to their advantages.

Conclusion

It would be wrong to say that the creators new concept do not offer the consumer anything useful at all. On at this stage development of the segment, the advantage of a curved TV screen over a traditional flat panel is not yet very obvious, but it exists. At least, the merits of this solution are confirmed by mathematical and geometric calculations. Really, what good are they if the viewer himself does not feel noticeable improvements during the viewing process? One way or another, there are opinions that in the future it is the concave screen that will survive as more rational and optimized.

When advertising their products, sellers assure buyers that their purchase will allow them to get the “IMAX effect” in their own apartment. But is the presence effect really so pronounced as to clearly give preference to models with a curved screen? Our article is dedicated to finding answers to this question.

The appearance of the first television receivers with a curved, or more correctly, concave, screen on the market happened a few years ago. Manufacturers of LCD panels, therefore, made another attempt to attract buyers. The models differed not only original design, but also because viewers received new sensations by watching videos or TV programs.

The most active promoters of new models were LG and Samsung. Thus, the statistics of models produced by Samsung in 2015, the total number of which reached fourteen, is as follows:
five corresponded to the curved format;
three models were produced with both a flat screen and a curved one;
only six had a flat screen.

Compared to the above-mentioned companies, Panasonic looks like an unconditional conservative in this matter. However, among their products there are models equipped with curved screens, and not in the only version.

What's attractive about these models?

According to the manufacturer, thanks to this design of the screen, it is possible to increase its visible size. After all, when watching programs on a traditional flat screen, the viewer is not provided with a uniform color perception of the picture. This is due to the fact that the distance to the left and right borders of the screen is somewhat greater for the viewer’s eyes than to its middle. This means that the glow of these zones passes past the axis of human vision.

It was to solve this problem that it was proposed to bend the screen so that it fits into the radius of a circle, the diameter of which was from four to five meters. At the same time, the viewer gets the impression that the model’s size is increasing, and the screen, which has a diagonal of 55 inches, is perceived as sixty inches.

In addition to the fact that there is a visual increase in the width of the screen. Positive characteristics of curved panels also include increased viewing angles, improved contrast characteristics and a reduction in glare and reflections.

What are sellers keeping silent about?

For example, they forget to mention that the magnitude of the real increase in perception is directly dependent on the distance at which the viewer is located from the TV. So if you watch programs on a 55-inch diagonal TV from a distance of five meters, then the increase will not exceed 3%, that is, it will be practically invisible to the viewer.

Another point that manufacturers prefer not to mention is what the area is that allows for comfortable viewing. But it is located within the sector that limits the field of the TV. And if for users of a flat panel the resulting picture looks approximately the same, then for those who use curved ones, the value of the sweet spot - the best location when viewing - should be taken into account. This means that any violation of the boundary that is comfortable for viewing will lead to the leveling of the advantage that a curved screen has.

The viewer, who is not at the point called the sweet spot, but located on the left or right side of it, has an improved view of the side of the screen that is located farther from him. While the visibility of the near edge is significantly worsened, which is due to the sharper angle at which the image hits the viewer’s retina. This phenomenon gives grounds to assert that there is a decrease in visibility compared to the usual flat panel. And some users also say that there are also certain geometric distortions.

In addition, it should be noted that all concavity artifacts will affect the perception of viewers to a lesser extent than larger size screen. Therefore, a real result should be expected provided that its diagonal is at least 55 inches. And the bulk of the units we sell are equipped with 40-inch screens.

According to experts, in order to achieve the effect of presence, the screen must cover at least 40% of the field of view. This means that if the screen has a radius of curvature of five meters, then either the diagonal of the screen must be more than one hundred inches, or the viewer must sit very close to the screen.

Today's realities are such that it is preferable to install concave displays on monitors rather than on TVs. After all, most often, only one person works at the computer, who is located fairly close to the screen. This allows you to achieve the effect of presence even with such a relatively small diagonal as twenty-seven inches from a distance of about sixty centimeters.

About the positive and negative sides of the concept

Of course, the positive thing is that with the help of a concave screen it is possible to effectively combat such a disadvantage as a decrease in the contrast ratio at the edges of the display. However, this is best demonstrated on TN matrices, which are most often used in budget devices, having a small diagonal. When using IPS matrices or VA used on expensive TVs, this advantage is leveled out.

The obvious disadvantages of concave screens, of course, include the presence of optical distortions, changes in the worst side viewing angles and contrast ratios for viewers located outside the comfortable viewing area. It should also be remembered that the video material broadcast on the concave screen was filmed without taking into account its design features. After all, the modern film industry is focused on reproducing its products exclusively on a flat screen.

Due to the increase in the cost of producing concave screens, compared with the production of flat models, the buyer of curved screens will have to face a significant increase in cost, which, according to experts, is not entirely justified by the added advantages. In addition, the so-called blind tests conducted by online publications suggest that the majority of viewers cannot immediately find the difference between the operation of flat and curved panels. And this allows us to assert that there are no significant differences that surprise us with novelty in the process of transition from flat panels to curved ones.

If we go back to 2013, we see the first signs that a curved TV screen may be destined to become the next “3D”, especially judging by the marketing activity of Samsung and LG, which demonstrated the first curved OLED TVs. At the beginning of 2014, we once again encountered this trend when CES 2014 opened, but then everything was much more serious, as Samsung released curved LCD panels. But what are the benefits of these curved TV screens? Perhaps TV manufacturers have found a solution to some problem that we didn’t even know about? And if so, what is this mysterious problem they're trying to fix? Let's find out!

Where are curved screens used?

Actually, curved screens are not new. They have been used in many cinemas for a long time. Many TV viewers probably also remember the era of CRT TV, when a cathode ray tube (CRT) had a curved plane that served as a screen (although they were convex, not concave). And in cinemas, a curved screen solves two specific problems:
The lens of a film projector is almost a point source of the image. The light beam from this source is more optimally projected onto a concave-shaped screen, otherwise the level of distortion increases towards the edges of the screen. This effect is also known as pincushion distortion.
The typical distance from the screen to the audience in a movie theater is short, so a curved screen is needed to expand the “field of view,” which minimizes the need to turn your head to follow an object flying across the screen.

Imperial Cinema in Copenhagen

If you've ever truly enjoyed watching a movie in an IMAX Dome theater, you'll understand why a curved screen can provide a truly immersive experience while you're in a dome that almost hugs you completely.
Before we get to the main topic of the article, let's introduce another concept that we will often use later, well known as the “sweet spot”, which in our opinion corresponds to the optimal place for the viewer, the comfortable viewing zone. The optimal place for the viewer in such a cinema is the center relative to the arc of the curved screen, from which all lines to the screen are perpendicular to the viewer’s eyes.

How did manufacturers contribute to the emergence of curved TVs?

Right from the moment curved screens hit the market, we weren't exactly spoiled with precise calculations of the real merits of these new TV panels, and so far we can only get vague explanations related to the comparison of curved screens versus flat ones.

Samsung and LG immediately began popularizing the curved screen as "providing greater immersion" and enhancing the 3D experience because "the screen almost surrounds you." Along the way, “improved” viewing angles became the object of discussion, along with reduced image distortion and increased contrast.

LG has been telling people about an incomprehensible “goropter line” that defines points on the screen that are equidistant for both eyes of the viewer. Or, in other words, it is an arc in the center relative to which you are located. If the surface of the TV screen is at a distance corresponding to the horopter line, your eyes You won't have to adjust the focus when viewing the screen, the company believes. There are theoretical and empirical models that do not completely match, and LG decided to adopt the empirical version, which describes a smoother arc (larger radius of curvature) than in the theoretical model.

Click on the picture to enlarge it

LG and Samsung also claim that a curved screen will appear larger to the viewer than it actually is. In the picture below, LG illustrates the added width you'll get by choosing a curved panel. Notice how close the viewer is sitting to the screen.

Click on the picture to enlarge it

But what do we really have?

Let's take a closer look at all the arguments in favor of a curved TV screen. Naturally, today's screens are curved only in the horizontal direction.

"More Immersion"

To ensure the attractiveness of a curved TV screen for buyers, first of all, it should be increased involvement in what is happening on the screen, or, as is commonly expressed in marketing slang, “greater immersion.” Does a curved screen actually provide "more immersion"? The answer is clear: yes. But only if the screen envelops the viewer, as in IMAX. You will then “feel much more immersed in the plot of the film” (whether you like it or not is another matter). The same thing happens if you are sitting in the front row of a movie theater. But the key factor here is screen size! Because if you want the screen to "encompass" you, it must have enough large size relative to the distance from the viewer to the screen. This is quite difficult to achieve with a 55'' TV. Especially if your favorite sofa is already located at a slightly further distance from the TV screen.

According to THX's screen distance guidelines, to achieve a immersive experience, you should sit at a distance from the TV where the screen covers 40% of your field of view. To meet these requirements, you should be sitting about 1.7 meters away from a 55" TV. But this is already too close for a Full HD screen. At 1.7 meters from the screen, you should already be thinking about upgrading the resolution to 4K But this is a completely different problem.

So what does this mean? Well, if you go by the horopter line theory, the latest curved 55" OLED TV needs to be viewed from a distance of 5m from the screen. This is significantly further than THX recommendations. So the radius of curvature of the LG OLED TV is actually quite far from optimal if you strive for immersive immersion, simply because the TV screen is too small to provide optimal overview from a convenient place.

For a screen with a curvature radius of 5 meters, its diagonal must be 101 inches to achieve a fully immersive movie experience. Samsung is actually starting to sell a TV in this size, but unfortunately you won't be able to buy it.

Wider viewing angles and contrast

The next argument made by proponents of a curved screen is the supposed expansion of viewing angles (the same arguments are used as for improved contrast). But do we need this? If we talk about TVs in general, the answer is not clear-cut, but if we take into account OLED TV, then it’s clearly not necessary.

U OLED TVs There are no problems with either contrast or viewing angles, they are already excellent. For LCD TVs, there is a need to expand viewing angles and contrast. This is especially true for LCD viewing angles Samsung TVs and LG TVs when it comes to discussing contrast.

So, how can a curved screen help here?
The curved screen can compensate for the loss of contrast in the side areas when you sit very close to big screen. This will be especially obvious if you purchased a monitor large diagonal based on Twisted Nematic (TN) LCD panels. It's very common to get drastic drops in contrast at the edges of the screen simply due to increased corners. In general, this is a serious problem that has negative influence for color rendition.

The typical user distance from the monitor is about 60 cm and, with a screen size of 27 inches, you will notice the positive effect of the concave shape of the screen - especially since more than one person rarely sits in front of the monitor.

When it comes to watching TV, things are a little different. First of all, not everyone prefers to watch TV alone. But there is only one place with optimal viewing angles in front of the screen. It should be noted right away that a conventional flat LCD screen also only has one optimal position in front of the TV screen, from which you have the same angle relative to the left and right side of the TV panel, so the optimal position in front of the screen does not only apply to curved monitors. But here we are only talking about the advantages of curved screens over flat ones.

Are there any benefits to a curved screen in terms of improving viewing angles when more than one viewer is sitting in front of it? Again, we have to take into account how you will be positioned relative to, for example, a 55" TV screen that is only about 120cm wide, as someone may end up quite far from the center center line towards the screen.

Click on the picture to enlarge it

As soon as you move away from the center, the angle relative to the near edge of the screen begins to shrink (less than 90 degrees) ( acute angle), and the far angle increases by more than 90 degrees (obtuse angle). Eventually, this may end up in a situation where one side of the screen is almost parallel to your line of sight (you probably wouldn't want to watch TV from that position anyway).

Changing the viewing angle of course also applies to the flat version of the screen, but here the changes are not as dramatic when you move a little away from the center of the screen. But not only does contrast depend on the viewing angle of LCD panels, you will also experience similar problems with black levels and color reproduction when you move away from the center.

The picture below shows the corner sector in front of the screen, where you get the maximum benefit from choosing a concave screen instead of a flat one. Keep in mind that all TV viewers should be positioned within the green zone to benefit from the concave surface of the screen when it comes to viewing angles, black levels and color reproduction. But almost everything is not as strict as shown in the figure; the picture on a curved panel does not automatically become poorer immediately after leaving the green zone.

It goes without saying that the closer you move the sofa to the TV, the more people you will be able to place on it (in the green area). It is also obvious that the increased radius of curvature will allow more people will fit inside the optimal area if you are alone on a distant sofa. Anyone outside the green zone will have more limited angles.
Let's take a look at how many people can actually fit comfortably in front of a curved 55-inch TV screen. Let's increase the radius of curvature so that it is proportional, for example, as in the example with LG, to a distance of 5 meters from the screen, and see where we can fit in front of the screen. The typical viewing distance is about 3-4 meters and at this distance it is quite difficult for two viewers to get into the green sector.

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Thus, the answer to the question “Do they become better angles views on a curved screen?" - affirmative as long as you sit in a certain area.
Ironically, not all types of LCD panels actually benefit equally from the concavity of the screen. Samsung's VA panels suffer most when offset from the central axis towards the screen, so TVs with this type of panel are preferable to watch from directly in the center of the screen, in any case.

Less optical distortion and a more uniform focus plane

Okay, now let's look at the arguments about reducing optical distortion and eliminating focus shift. Here, the convincingness of the producers’ position is generally far from clear. Firstly, the sensor matrices used in video cameras today are flat in shape, so this video is intended to be viewed on a flat surface.

The depth perception of scenes in films is designed to be reproduced on a flat screen, and by showing it all on a curved surface, you distort the original intent of the director of the film. We experienced this while testing one of LG's OLED TVs. One of the complaints in that review was that it actually added optical distortion that was very noticeable when looking at the screen from a high angle.

Now let's see what the situation is with the focal length? TV manufacturers claim that your eyes will be more relaxed when the entire image on the screen is in the same plane of focus. This might be true if the change in focal length were significant. When viewing on a curved and flat screen, you will have a difference of about 6 cm at the edges, relative to the center of the screen of a 55" TV. If, when you sit at a distance of 3-4 m from the screen, your eyes suffer from defocus with a change of about 2 % distance to objects, then you need to urgently consult an ophthalmologist.

Everything you do during the day requires your eyes to constantly change focus. They are designed to do this at ease. And here you don’t need to adjust or invent anything.

Reducing reflections

Now let's see what we have with reflections from a curved screen? With the curvature of the screen plane, the angle of reflection for rays of light incident from external sources.

Thus, due to this, it is possible to reduce the glare effect on the screen. Due to the concave shape, the so-called focal point will be located at a distance of half the radius of curvature from the center of the screen. For a radius of 5 meters, this means that the focal point is 2.5 meters from the center of the TV screen.

What does this mean for you? Reflections are blurred if you sit further away from the focal point, they will become blurrier the further you sit. Thus, due to the curvature of the screen, the glare effect is reduced. Due to the expansion of reflected objects, the further you sit from the screen, the more their light intensity decreases.

This phenomenon is also starting to be used in portable displays, which you may soon see in practice. The immediate benefit will be noticeable when you use your mobile phone in brightly lit conditions.

The screen will appear larger than it actually is

Yes, that's how it is. But really, this is just a variation on the earlier discussion about the optimal distance from the viewer to the screen, because with a curved screen, the edges of the screen are brought closer to you. Let's just see what you actually get.
The figure below shows the perceived width of the screen depending on the viewing position. As you can see, the added perception of width decreases as you move away from the screen.

To evaluate how much you'll actually benefit in terms of added screen size, let's consider a 55-inch curved screen. For a 55" (140 cm) diagonal screen, the curved shape will reduce the projected width to 121.7 cm when the flat version is 122 cm. Given a radius of curvature of 5 m, this means that the screen forms part of an arc with an angular sector of 14 degrees when you sit at the optimal point. An angle of 14 degrees will give you about 3% more width than a flat 55-inch screen. A little. What if you move closer to the screen? At 3 meters from the screen, the angle increases to 24 degrees, which will give you an additional 9% of the perceived screen width.

For those who are strong in geometry, below are the basic formulas that must be used for calculations. You can check all the calculations.

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The graph below shows how perceived width varies with screen angle. As you can see, the effect of a curved screen decreases as you move away from the screen (i.e. the viewing angle of the screen decreases):

Click on the picture to enlarge it

Conclusion

Advantages compared to a flat LCD screen:
Reducing reflections
The TV screen is perceived as larger than it actually is
When used in monitors, wider viewing angles and improved contrast can be provided for a single user

Disadvantages compared to a flat LCD screen:
Viewing angles deteriorate for viewers sitting off-center in front of the screen
Reduces contrast for viewers sitting off-center in front of the screen
A TV mounted on the wall looks less elegant (but this is a matter of taste)
The overall thickness of the TV increases
Higher production costs and therefore higher TV prices
The curvature effect cannot be turned off...

2014 was the time when TV manufacturers tried to convince us that our current TV screens were not very advanced compared to the curved shape. However, they have not presented serious evidence of the imperfections of the flat screen, but as we have seen many times before, the marketing machine is up and running regardless of the weight of the arguments used. Many probably still remember how manufacturers tried to mislead us, assuring us that “LED models” are new look TVs, and not just an LCD TV, in which they replaced the backlight lamps with LEDs.

Every year new television technologies and marketing terms appear. The predecessors of the curved screen are buzzwords such as "3D", "Smart TV", "dynamic contrast", "xxx Hz" and "sharpness". The current technological scourge differs from previous ones in that it cannot be turned off. Even the Ambilight effect Philips TVs, which also greatly affects the physical perception of the screen limits, can be turned off with the touch of a button. Now we are faced with a technology that cannot be ignored. "Curved display" cannot be disabled. Bye! Samsung and LG hope in a year or two to make us happy with TVs, the degree of curvature of the screen of which the viewer will be able to adjust from the remote control. And if necessary, make it completely flat again.

It may be hard to understand, but TV manufacturers will now be trying to sell us products that are actually a step backwards in terms of picture quality for most of the home TV audience, except for the lucky one sitting in a perfect position in front of the TV. Poor viewing angles have previously been a problem that manufacturers have had to contend with due to the limitations of LCD display technology, but now they seem to be ruining their successes. At the same time, some manufacturers still produce their flagship and other models high class only with flat screens, otherwise the development of the industry may receive momentum in a very wrong direction.

We hope that you, dear consumer, will not be blinded by the radiant imagination of marketing campaigns designed to ensure sales that are hot as cakes. In this whole undertaking one can see just another attempt to promote the next “3D”.
Dear manufacturers, bring back flat screens to us and demonstrate curved ones at exhibitions and shows!