- Display terms
- Picture Inaccuracies
It can be hard to keep track of televisions with so many technical terms in use. This is why we made a list of all the technical terms we use. They are sorted alphabetically in their categories. If you’re missing a terms explanation, please let us know in the comment section at the bottom of the page. We will then add the term as soon as we can. And now we wish all cinema enthusiasts a lot of fun while browsing through our encyclopedia.
Dolby Atmos is a sound format that adds height channels to surround sound. Accordingly, a sound system with Dolby Atmos not only has center, satellite speakers and superwoofers, but also speakers that are aligned in such a way that they enable the sound to be radiated from above to the listener. This enables a new sound level, so that the sound of a helicopter’s rotor blades, for example, actually comes from above. In addition, the signal is object-based, which enables three-dimensional coordination and thus a realistic soundscape. A competing format from DTS would be DTS:X, for example.
Dolby Vision is a dynamic HDR format. Dynamic means that the Tone-Mapping Curve can be adjusted scene by scene. In theory Dolby Vision supports a color depth of up to 12 Bit and can be mastered at a maximum luminance of up to 10,000 Nits.
Dolby Vision IQ
Just like Dolby Vision, the tone mapping curve is dynamically adjusted. However, it is now also adjusted to the ambient brightness by using a light sensor. The HDR10+ Alliance has a counterpart, HDR10+ Adaptive, whose functionality is very similar.
DTS:X is the competitor format of Dolby Atmos. It is also an extension of the surround sound with height channels with object-based sounds.
HDR – High Dynamic Range
HDR is a format which contains metadata enabling a larger dynamic range (contrast) and a larger color gamut. It is often used as a generic term for the different HDR formats like HDR10, HDR10+ and Dolby Vision. Find more about HDR here.
HDR10 is a format with colors in the Rec 2020 color space and a 10 Bit color depth. HDR10 movies are usually mastered at a maximum luminance of 1000 Nits.
HGiG – HDR Gaming Interest Group
HGiG is designed to enable HDR gaming with popular consoles such as Playstation 5 or Xbox Series X. It is not a true standard like Dolby Vision or HDR10+. It is not a real standard like Dolby Vision or HDR10+, but rather a kind of alliance between game developers, TV & console manufacturers to enable the best possible HDR performance in gaming.
However, since it is not a real standard, there is no uniform approach and the ideas of the different manufacturers can be far apart.
HLG – Hybrid Log Gamma
Hybrid Log Gamma is simplification to transmit and emit the SDR and HDR Signal. Both Signals are combined into one and therefore only one Signal has to be emitted by the live broadcaster. This reduces the amount of data that has to be sent by the broadcaster without causing any data losses. HLG is mainly used to process 4K content at 100 Hz without affecting the image quality.
SDR – Standard Dynamic Range
Standard Dynamic Range is used for “normal” videos without HDR, with a conventional dynamic range and gamma curve.
[email protected] is an abbreviation to describe that the TV’s panel has a native 4K resolution and the refresh rate is 120fps. However, this does not say anything about whether this potential can also be used for gaming. An HDMI 2.1 interface is still needed for that.
The color depth is measured in Bit. 8 Bit stands for 28 different values for each color channel. For TVs those are red, green and blue. By combining the 3 rgb channels 28*28*28=16.777.216 colors are possible. If the color depth isn’t high enough banding can occur. HDR10 or the dynamic HDR formats, like Dolby Vision, work with 10 or even 12 Bit.
Black Frame Insertion
Black Frame Insertion, or BFI for short, reduces motion blur by inserting additional black “blank frames” as intermediate images. The result: movements appear clearer and finer. Since only real, unaltered frames are displayed on the screen with this method of blur reduction, the number of frames per second is irrelevant – regardless of whether it is 60 or 24. Another advantage: The well-known soap opera effect does not occur. Disadvantage: The picture is displayed darker overall and some people may experience an undesirable flickering effect.
The contrast ratio describes the ratio of the darkest black and the brightest white that can be reproduced by a TV.
Direct Lit Backlight
In direct lit backlights LEDs are arranged in a matrix behind the liquid crystal layer of an LED LCD TV, which is used to illuminate the TV. This matrix arrangement usually ensures a more even illumination.
Edge Lit Backlight
If an LED-LCD TV has an Edge Lit backlight, this means that the LCD layer is only illuminated from the edges. This is cheaper than integrating an additional LED matrix behind the liquid crystal layer.
The gamut is the amount of colors or color tones a screen can display. For HDR a wide color gamut is reThe human eye can perceive a certain color range. The colored light can have a wavelength of 380nm to 780nm. A display device such as a TV cannot usually cover this entire color range. Therefore, different color spaces are defined, such as sRGB, DCI P3 or Rec.2020 – which indicate a color range that can be covered by the TV in percent. The larger the coverage, the more colors can be reproduced in a precise manner by the TV.
The color space or gamut is a surface, i.e. a two-dimensional plane with X and Y coordinates that reflect the individual RGB colors. The color volume also includes the brightness or luminance of the colors to be reproduced, which is especially important for HDR material, since it is reproduced much brighter.
Hertz is the derived SI-unit of frequency with 1Hz=1/s . When talking about TVs this means how many different pictures a TV can display in one second (=refresh rate). It usually is a fixed number and should not be confused with frames per second (fps). But there also are TVs with a VRR.
The Input Lag is the amount of time (latency) a TV or monitor needs until displaying the input signal on the screen. A low input lag is especially crucial for video games. If the input lag is below 20ms most people won’t notice it.
With most inputs being 30fps or less, a TV with a refresh rate of up to 120Hz can use interpolation to calculate the missing frames. This makes motion appear smoother yet it can also cause the Soap Opera Effect.
IPS – In Plane Switching
IPS is a type of LCD panel. The advantages of In Plane Switching are a usually short response time and a wide viewing angle. The black level and contrast ratio isn’t as good as with other types of displays though.
A Liquid Crystal Display (LCD) is a type of display, which uses said crystals to polarize the backlight resulting in the picture you see.
Motion Handling is the general term for how well a TV is displaying moving content.
A Nit is the SI unit of luminance: 1 nit = 1 cd/m2 meaning the luminous flux (or luminous power) per projected source area. Average and maximum luminance are the best way to compare the brightness of different displays.
The acronym OLED stands for “organic light emitting diode”. The advantage of this display technology is that the organic LEDs are self-luminous (electroluminescence) and thus no backlighting is needed like in LED-LCD TVs.
They can produce an almost perfect contrast of infinite:1 and are extremely viewing angle stable.
A pixel is the smallest picture element of a TV. It can reproduce a color and a brightness value and is arranged in a grid with many other pixels, which in their entirety represent the image. The resolution is used to express the number and arrangement of pixels.
In cameras, a pixel is the smallest recording element.
The pixel density in pixels per inch (ppi) indicates how many pixels are in one square inch (~6.45cm²). It can be calculated by the resolution and the size of the display and indicates the level of detail of a display.
The pixel density is smaller for large TVs with the same resolution, which is why blurring can be visible here if the viewer is too close to the TV.
The response time is the time it takes a pixel to change its color. Usually, the time a pixel needs to reach 80% of a full transition from one basic color (RGB) to another is measured. The response time is amongst the most important aspects for determining a TV’s motion handling. If the response time is too high it will be visible as motion blur.
The resolution or image resolution is a specification that indicates the number and arrangement of the pixels of an image or a display device. For televisions, it indicates how the pixels are arranged and how many there are in total (native resolution).
If the pixels are grouped to display a lower resolution, however, we no longer speak of a native resolution, but of a displayable resolution. The common native resolution for TVs is UHD, i.e. 3840×2160 pixels. This corresponds to an aspect ratio of 16:9, which is also a standard for TVs.
Tone Mapping is roughly a kind of translation from the contrast ratio and brightness of captured content (movies & photos) related to the brightness and contrast range of the display device.
VA – Vertical Alignment
VA is a type of LCD panel. Advantages of Vertical Alignment are deep blacks and a high native contrast ratio. The viewing angel on the other hand isn’t too great.
VESA is an abbreviation for the Video Electronics Standards Association. It is commonly used for their standard for the mounting interface: Flat Display Mounting Interface (FDMI). The two numbers of a VESA FDMI (e.g. 600 x 400) are the horizontal and vertical spacing between the screw threads.
The viewing angle indicates how oblique the viewer can be to the TV without causing picture quality degradation. The degradation can manifest itself through various factors. For example, loss of brightness, black crush, color shift or washed-out colors can be noticeable.
ABL – Automatic Brightness Limiter
An ABL is a kind of protective mechanism that is used in OLEDs, for example, to prevent the organic LEDs from overheating. Large-area bright image contents are darkened for this purpose.
ALLM – Auto Low Latency Mode
With an Auto Low Latency Mode, the TV recognizes a connected console of a newer design by itself and automatically switches to game mode to keep the input lag as low as possible.
Calman – AutoCal & Calman Ready
If a TV has AutoCal, this means that the colors and brightness levels of the display can be calibrated automatically as far as possible using the Calman software from Portrait Displays and a compatible measuring instrument (colorimeter).
The term Calman Ready describes the same function.
Dithering is a technique used to display colors the TV normally couldn’t display. It is most commonly used to display a 10 Bit color depth with an 8 Bit display.
Edge Lit Local Dimming
If an LED LCD TV has Edge Lit backlighting, where the LEDs in the frame can be clustered and dimmed individually, it is referred to as Edge Lit Local Dimming.
FRC – Frame Rate Control
Frame Rate Control is a certain type of dithering. With rapid cyclic switching between two different color tones a color tone in between the two is simulated.
Full Array Local Dimming
Full Array Local Dimming is the combination of Direct Lit backlighting on LED LCD TVs, whose LEDs are grouped into zones that can be individually controlled and dimmed.
The term linear television describes the traditional television stations that broadcast their program sequentially. This can be received, for example, via cable, satellite or antenna.
Local dimming is a function that can be used on LCD TVs with LED backlighting to improve contrast and minimize blooming.
For this purpose, the LEDs of the backlight are grouped into zones that can be dimmed independently of each other. This function can be used on TVs with Edge Lit backlight as well as Direct Lit backlight.
PVR – Personal Video Recorder
With the PVR feature a TV can record the program onto a USB device like a HDD or Stick.
If a TV has a twin tuner, it has two tuners integrated. This allows two separate TV signals to be received simultaneously. This is only relevant for linear TV, when you want to watch one TV channel and record another program at the same time. If a TV does not have this feature, it is called a single tuner.
VRR – Variable Refresh Rate
A TV supporting a variable refresh rate can adjust its frequency to the output frequency of a connected graphics card with the same feature. This not only reduces the input lag and improves a games motion handling, but it also prevents tearing.
Artifact is a term used for picture inaccuracies/errors as a result of the TV’s hardware or picture processing.
Black Crush is the loss of detail in dark scenes. For example the TV cannot display shadows on very dark clothing or it crushes bright stars in the night sky.
The problem of banding is if you can notice steps in color tones in a gradient.
Blooming describes an unwanted glow around bright objects on a dark background. The reason for blooming is the backlight. Some televisions try to fight blooming with their local dimming algorithm. The edges of bright objects are dimmed down to do so. This can result in “reverse blooming” though.
Burn-in stands for the “burning in” of an image into the panel, so that it is still recognizable when another image is displayed. Nowadays, only TVs with OLED panels are affected, but plasma and tube TVs were also affected, so it is by no means a new phenomenon.
Current OLEDs have various protection mechanisms integrated to minimize burn-in. The Automatic Brightness Limiter is one of the most effective mechanisms.
Clouding, or flashlighting, is used for bright spots (clouds) resulting by the backlight, local dimming feature or the resulting change in temperature. Clouding is most common on the edges or corners of LCD TVs.
In clipping, parts of the image are clearly displayed too brightly. At such points, details can no longer be perceived by the viewer because the necessary image information is simply missing. This effect occurs when you set the contrast and brightness too high. The opposite is true for black crush.
Dirty Screen Effect
The Dirty Screen Effect is an effect caused by the backlight, local dimming or anti-reflective coating. The same color looks slightly different in different areas of the screen. This is particularly annoying when watching sports.
Judder is the term for single frames staying on the screen longer than other frames. This inconsistency is due to the input frequency mismatching the TV’s frequency. For example when displaying 24p content on a 60Hz TV the TV has to display every second frame 2 or 3 times (3:2 Pulldown) as 24 doesn’t fit evenly into 60.
Screen-Tearing is an image error that can occur in both videos and games. It occurs when the display and the graphics card are not sufficiently synchronized with each other and the refresh rate of the TV is not sufficient to display all frames transmitted by the graphics card. This may cause that both images are displayed fragmented on the screen. For example, the upper part of the picture does not match the lower part and the overall result may appear cut or “torn”.
As static frames are displayed too long on the screen, motion might appear not fluid. This is especially noticeable in long panning shots. To fight this a TV can use motion interpolation.
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