#hdrtechnology

The first TVs sets appeared in the US back in 1929. Unfortunately, the size of their screen did not exceed the postage stamp. More modern models appeared in Europe only in 1942. But further evolution was rapid. The development of digital technology has further accelerated this process. Today the market offers flat, large, ultra-contrast, curved, smart, etc. models. Of course, this is accompanied by the complication of choosing the optimal TV. Of course, technical characteristics can simplify this task.

Diagonal

The screen size affects the viewing distance. Previously, experts recommended the optimal distance as 3-4 diagonals, later - 2-3 diagonals. Of course, this value is subjective and depends on the individual features of vision, content, screen resolution and other factors. For example, too small screen does not reproduce the small details of the image, but too large a screen is inconvenient for the perception of the whole scene and requires an increase in the viewing distance. Nevertheless, the Internet offers many calculation algorithms that you can use when choosing a model. One of them is given in the table. In any case, the dimensions of the TV should correspond to the room area.

Screen resolution

In a simplified form, this is the number of pixels on the screen. As known, pixels form an image. Accordingly, the image clarity is directly proportional to the number of pixels. Today, the market offers TVs with the following resolution. HD, 1366 * 768 pixels. Of course, these models are obsolete, but it's still used in budget models with a small diagonal. Screen with a diagonal of 52 or more inches displays an image of 1366 * 768 pixels as a collection of squares that, of course, reduces the pleasure of viewing. Therefore, today HD resolution is mainly used in TVs with a screen up to 24 inches. Full HD, 1920 * 1080 pixels. Today it's the most popular format because of very good price / quality ratio. Therefore, most of the media content is made in Full HD or HD resolution. UltraHD or 4K, 3840 * 2160 pixels. Unfortunately, today this resolution is only available in the models of the upper price segment. It provides maximum image clarity even for very small frame elements. Discussion about the advantages and disadvantages of Full HD and 4K models is quite active. The most common arguments in favor of Full HD: - high cost of 4K models; - offer of 4K-content is limited; - visualization of the advantages of 4K-resolution is noticeable at a distance of up to 32 inches, which is inconvenient for viewing. Of course, the final decision depends on the individual's preferences.

Type of matrix

Today, the market offers LCD/LED and OLED matrices. Unfortunately for many, plasma TVs are no longer produced.

LCD LED TVs

LEDs generate radiation, and liquid crystals partially or completely close the light source, forming a certain shade of color. These TVs use DirectLED or EdgeLED. DirectLED is located behind the matrix, and the LEDs in EdgeLED are positioned along the contour of the screen. EdgeLED uses a sophisticated reflector system that dissipates light throughout the display surface. Of course, this technology is cheaper, but it provides a less even distribution of light across the screen. Today many companies develop this direction, considering it more promising compared to OLED technology. PROS: - low price; - these models are very light and thin with minimal power consumption; - high brightness; - long service life; - good prospects for improving image quality due to new technologies (backlight on quantum dots, etc.). CONS: - low playback quality of black (gray or violet shades in black fragments of the frame); - relatively large response time sometimes creates an image plume in highly dynamic scenes; - distortion of color and contrast at an angle due to a relatively small viewing angle.

OLED TVs

Of course, these models are the most modern. They form an image with the help of matrix with organic LEDs that use light-emitting organic materials. Each LED independently emits light and does not require a backlight. Therefore, such screens are very thin and provide excellent playback of deep black color due to unlimited contrast. In fact, it creates the completely black dot on the screen when turned off. PROS: - perfect playback of deep black; - almost unlimited contrast and excellent color rendering; - wide viewing angles; - very low input lag. CONS: - high price; - reduced image quality in bright light. Of course, today the Internet in abundance offers various tests of image quality assessment of OLED, QLED and LED models. But, they are very individual and can differ significantly for different people. The video from LG at the end of this article demonstrates one of comparative tests between LG-LOEWE OLED vs QLED vs SONY LED - Santorini.

Screen refresh rate

The frequency characterizes the number of image updates in 1 second and is measured in Hz. But the human eye perceives no more than 60 Hz. 120 Hz is more comfortable for 3D video (60 Hz for each eye).

TV Sound

Thin lightweight body of modern TVs is not suitable for a powerful audio system. Therefore, most models provide a medium-quality sound. Of course, it's quite enough for television, but the home theater requires the purchase of a separate audio system.

Smart TV

Smart TV uses an operating system with built-in apps to view content from YouTube and other sources. The TV connects to the Internet via a Wi-Fi or cable with RJ-45 connector. Sony and Philips use Android TV, LG works on webOS, and Samsung - on OS Tizen.

HDR technology

The modern TVs are very complicated devices with lots of different technical values. Therefore, the choice of the optimal TV is rather complicated. Severe competition between companies is sometimes accompanied by not very honest marketing and often requires additional clarification.

LCD and LED screens

In fact, the LED screen is an LCD screen with an improved LED backlight that replaces the less efficient fluorescent backlighting. The diode matrix is located either along the edges (Edge LED) or along the back plane (Direct LED) of the screen.

Each of them has advantages and disadvantages, but, according to experts, Direct LED distributes the glow more evenly. Each of them has advantages and disadvantages, but, according to experts, Direct LED distributes the light emission more evenly. In addition, it provides a higher density of black.

But today the full-array is considered the best. It's used in models of the upper price segment.

LED, QLED or OLED

LED TVs can not accurately reproduce black color due to constant backlighting of pixels. The playback of dark scenes on the LED screen is accompanied by gray or purple hues. The invention of OLED screens on organic light-emitting diodes solved this problem. Each such pixel emits light independently of each other. In dark areas, it completely turns off, providing playback completely black. The high price is the main drawback of OLED models. But this factor will decrease as the technology develops. The relatively low image brightness is another feature of this technology. Comparatively inexpensive OLED-panels provide brightness at the level of 700-800 cd / sq m. (As known, 1 cd / sq m = 1 nit). For comparison, the brightness of LED-TVs reaches 1400-1500 cd / sq m. Therefore, their advantages over LED TVs are visualized only at night or in a darkened room. The cost of brighter OLED models (up to 2000 cd / sq m) is very high. Samsung QLED TVs are an improved LED version and compete with OLED TVs from LG companies. Quantum Dot technology, according to the company, expands the depth and improves color rendering. But nanocrystals also do not emit light and require a backlight. In fact, today the market offers OLED and LED TVs. Differences between images on QLED and OLED screens are virtually not perceived visually.

4K resolution

Constant increase in resolution is one of the main trends. Resolution is equal to the number of pixels of the screen and provides image clarity. Accordingly, the image quality depends directly on the number of pixels, i.e. from resolution.

Full HD is considered standard for LED TVs. This is enough to watch blu-ray movies and digital channels in the HD TV standard. UHD (Ultra HD) or SUHD (Super Ultra-high-definition) resolution is 4 times higher compared to Full HD. SUHD uses Quantum Dot technology, and UHD is based on LED (liquid crystals or light-emitting diodes). But limited offer 4K content inhibits the development of this segment. Today 4K resolution is available only in expensive flagship models. Additionally, UHD provides high quality only on a large enough screen with a diagonal of 55 inches and higher. The distance to the screen also affects the visualization of the playback quality that decreases in direct proportion to the distance. The difference in perception between Full HD and UHD is practically absent at a great distance. But the distance of 32 inches for a TV with a diagonal of 55 inches will be inconvenient for many people. Sometimes little-known brands offer 4K models at very low prices due to savings on matrix and CPU performance. But 4K-content playback by such a TV is often accompanied by poor color rendering quality and regular image hanging due to very long input-lag.

Support for HDR (dynamic range)

As known, HDR technology affects the gradation of colors ranging from the brightest white to the darkest black and provides the correct color rendering that affects the image realism.

This technology provides more shades in shaded or too-lit areas. HDR technology requires a powerful processor, high brightness and HEVC (or VP9-Profile2) decoder. The maximum reserve of brightness should be many times greater than traditional TVs. HDR provides up to 1500 nits compared to 400 nits for standard models. The expanded color palette also requires special technologies. Today, a combination of these complex technologies is available only in expensive 4K-models. Modern 4K TVs with HDR support have a UHD Premium certificate. HDR function is indicated in the description as HDR10, HDR10 +, Dolby Vision or HLG. 4K Blu-ray format supports HDR by default. Unfortunately, this technology also requires special content that significantly limits its capabilities.

Diagonal

The diagonal affects the optimal viewing distance. A factor of 1.6 is usually used for LED TVs. Thus, a distance of 64 inch is optimal for a 40-inch model. Accordingly, the optimal distance increases with increasing diagonal size. Full HD TVs use the formula diagonal = distance (in meters) x 25 (factor). Thus, a distance of 2 meters is optimal for 50 inches. UHD uses a factor of 39. In this case, a distance of 2 meters is optimal for 78 inches, that, of course, is impressive.

Curved and flat screen

Curved screen visually increases due to the use of peripheral vision. But this effect is achieved only on models with a diagonal of 50 inches and above.

Today, many experts cite fairly convincing arguments against curved models. You can see them on the video at the end.

3D