8K televisions have several challenges ahead. It is evident that it will not be easy for them to prevail over devices with a 4K UHD panel until they convince many of the users that they really offer added value compared to these latest televisions. The absence of native 8K content does not help, but neither does the fact that two of the brands that are most strongly betting on this technology do not agree on the conditions that 8K televisions must meet.
LG and Samsung have held mixed positions for months. The 8K televisions of both brands scrupulously respect the resolution that the panel of a device with this technology must have (7,680 x 4,320 dots), but this is only one of the conditions that an 8K television must meet. What has caused the dispute between both brands is the way in which the contrast modulation of these televisions is measured and the relevance that this parameter has acquired. Without digging further, it is difficult to know who is right, so we have taken the path that always leads us to a successful conclusion: we have spoken with the brands involved in this conflict.
This is how an 8K television should be according to CTA, ICDM and the 8K Association
To put into context what LG and Samsung have told us, it is important that we know what characteristics an 8K television must have beyond the resolution of the panel. The funny thing is that there is not a single criterion accepted by the entire industry. There are two: the one that proposes CTA ( Consumer Technology Association ) and the one that defends the 8K Association. The first of these entities is an American standardization organization that represents the interests of more than 2,200 consumer electronics companies, including LG, Samsung and Sony, which, as we all know, are three of the brands with the most force are betting on 8K televisions. An interesting note: CTA is the association that organizes CES, the consumer electronics fair that is held every year in Las Vegas in early January.
There is no single industry-accepted standard that defines what requirements an 8K television must meet. There are two: the CTA and the 8K Association. And there are also two logos
The 8K Association pursues a purpose similar to that of CTA, but its scope is limited to the express promotion of 8K technology. Some of the brands that are part of this organization are Panasonic, Samsung, Hisense, TCL or IMAX, among others. The requirements that these organizations have established to define how an 8K television should be are not very different, but it is worth reviewing them in some depth to understand what has been the spark that has ignited the discussion between LG and Samsung. These are the conditions imposed by CTA:
- The television must incorporate a panel with a native resolution of at least 7,680 x 4,320 active pixels and a 16: 9 aspect ratio.
- It must be capable of receiving and processing video signals with a resolution of 7,680 x 4,320 dots and a color depth of 10 bits.
- It must have one or more HDMI inputs capable of accepting video signals with a resolution of 7,680 x 4,320 dots; 10-bit color depth; a rate of 24, 30, or 60 frames per second; the HDR transfer function, the colorimetry specified by the BT.2100 standard and the HDCP 2.2 content protection protocol.
- It must be supported by a processing engine that is capable of scaling content with a standard resolution, Full HD and 4K UHD to 8K.
Now we go with the characteristics that according to the 8K Association must respect 8K televisions. Its description is similar, although it is also more concise than the one proposed by CTA:
- These televisions must incorporate a panel with a native resolution of 7,680 x 4,320 dots.
- They must be able to process 8K video signals with a rate of 24, 30 and 60 frames per second.
- They must have a maximum brightness delivery capacity of at least 600 nits.
- They must be able to process video signals encoded in HEVC format.
- The signal from external sources must be transported through an HDMI 2.1 interface.
The statement that this organization published when it approved these specifications does not reflect anything else, but in the last section it reveals that 8K televisions must also meet other requirements that are only available to members of the association. Possibly these additional specifications describe what color subsampling these televisions must work with, what minimum color coverage they must guarantee, what maximum and minimum brightness values they must deliver to correctly reproduce HDR content, etc.
The requirements proposed by CTA and the 8K Association are so aligned that there seems to be no reason to explain the origin of the conflict between LG and Samsung. To find him we have to introduce one more variable in the equation: the organization ICDM ( International Committee for Display Metrology ). This is an international standardization association dedicated to designing the analytical methods used to evaluate the performance of display devices. And here finally comes the origin of the conflict: according to ICDM 8K televisions must have a contrast modulation value of at least 25% to play video, and not less than 50% to play text and still images at 8K resolution .
What is the problem? Simply put, LG’s 8K TVs meet these requirements, and Samsung’s don’t. In addition, to curl the curl, CTA has taken the form of measuring the contrast modulation proposed by ICDM. And this has encouraged LG to legitimately reflect in the promotion of its 8K televisions how well they stand in this test, arguing, in addition, that their “real” 8K meets international standards in clear reference to the measurement of contrast modulation established by ICDM.
What is contrast modulation and why it matters to LG
The person from LG with whom we have spoken to seek answers to the questions that 8K televisions currently pose is Luis Navarrete, Product Specialist at LG Spain and a qualified technician with whom we have spoken on other occasions. In one of them, Luis explained in great detail how the processing algorithms that this brand has developed work to maximize the potential of the OLED panels of their televisions. And this time he tells us in a very didactic way what contrast modulation is and why it is important for LG.
Contrast modulation has nothing to do with contrast. It does not measure contrast; measures resolution. It measures how distinguishable the contiguous pixels are at different levels of brightness delivery. When the TV is working. To measure it, a column of pixels is turned on and the next one is turned off, so on, in between them. When the television is showing this image, the level of brightness and black are measured, and the measurements we have taken are introduced into a formula that gives us contrast modulation, “explains Luis.
Contrast modulation has nothing to do with contrast. It does not measure contrast; measures resolution »
“Ideally columns with pixels on should give us pure white, and columns with pixels off with absolute black. In this ideal case, we would obtain a contrast modulation of 100%. LG NanoCell televisions obtain a contrast modulation of 85% using this evaluation method, and OLEDs of 92%. This difference between one and the other is explained due to the higher level of black that OLED panels have, although both figures are clearly above the minimum values that CTA has defined in terms of contrast modulation “, states this technician from LG.
These figures clearly reflect that the 8K televisions of this brand come out well from this test, but Luis assures that they also meet the other requirements stipulated by CTA: “The panel of television may have the resolution required of a native 8K device, but It is important to know what happens when you are playing a video signal if at any given moment all your pixels are on or not because if they are not, something strange is happening. The organization CTA, which is one of the organizers of the CES, has established what requirements an 8K television must meet, and these conditions go beyond resolution. They propose a cadence of at least 50 FPS, 4: 2: 2 color coding and HDR, among other conditions, as well as a contrast modulation that must be greater than 25% to display 8K video quality, and over 50% to correctly reproduce text and still images at this resolution. ”
Samsung claims that contrast modulation is not being measured well
We already know LG’s vision, but we still need to dig into the other side of the coin to find out what Samsung thinks about contrast modulation and to what extent it reflects the image quality of an 8K television according to this company. The person we have spoken to this time is Toni Rull, Product Specialist and CE Training Manager at Samsung Electronics Iberia. Interestingly, during our conversation, Toni explained that Samsung initially proposed to ICDM to resort to contrast modulation due to how useful this parameter is when measuring the resolution of a panel.
“At the time Samsung asked ICDM to retrieve the concept of contrast modulation, but not the way it was measured because it is a useful way to assess resolution,” says Toni. This statement unhesitatingly underpins what for this company is the source of the problem: how contrast modulation measurement has been described. “In our opinion, when CTA defined it, it made the mistake of applying practically the same measurement system that was used in 1930. The problem is that due to our advanced anti-reflective systems the result of that measurement does not accurately consider the quality of the contrast modulation. ”
“ICDM keeps trying to see what is the best way to measure this parameter because the one that is being used is not the appropriate way to evaluate the 8K televisions that we have today”
What Toni tells us is interesting because, objectively, Samsung televisions use a very effective anti-glare coverage that places them one step ahead of most of their competitors in this field. We have been able to verify it first hand during the analysis of the latest televisions of this brand that we have tested, and it is one of the qualities that I appreciated in the QLED Q95T model that I analyzed just a few days ago. However, for someone outside of Samsung who does not know in detail how this anti-glare coverage is implemented, it is not easy to assess the impact it can have on the measurement of contrast modulation.
In any case, it is interesting to confirm that Samsung considers it a good idea to use this parameter to assess the quality of 8K televisions, but, at the same time, it does not agree with the procedure used to measure it. The only way to resolve this conflict requires finding a way to measure contrast modulation that satisfies all brands, and it doesn’t seem easy to do so.
Toni confirms that this is the challenge that this industry has ahead: «At this moment ICDM continues trying to see what is the best way to measure this parameter because the one that is being used is not the appropriate way to evaluate the 8K televisions that we have today. We don’t really want the pixel to be distinguished. Our televisions meet as many certifications as any other, but our communication policy does not emphasize comparing what we have and what our competitors have. ”
Sony claims its TVs perform well when measuring contrast modulation
Until now Sony, which has also opted to place 8K panel televisions on the market, has remained on the sidelines of the discussion around contrast modulation. Even so, we have contacted the Spanish subsidiary of this Japanese brand to find out their opinion about this conflict, and what they have told us clearly reflects that Sony does not object to the way modulation is being evaluated. Contrast: «LG Electronics defends that according to the latest ICDM standard an 8K television must have more than 33 million pixels and a contrast modulation value of 50%. LG’s 8K OLED TVs have 90%, Sony’s 80%, and Samsung’s only 12%.
“LG’s 8K OLED TVs have a CM of 90%, Sony’s 80% and Samsung’s only 12%”, according to Sony
The contrast modulation measures that LG and Sony have shared with us allow us to reach several interesting conclusions. The most obvious one is that the self-emitting pixels of LG’s OLED panels give them a clear advantage in contrast modulation measurement, something to be expected. On the other hand, the 8K NanoCell TVs from LG and the 8K from Sony, which use an LCD panel (the latter brand has not yet launched any OLED 8K TVs) show a contrast modulation that moves in the orbit of the 80 or 85 %. And, surprisingly, Samsung’s QLED televisions, which also use an LCD panel, remain according to the figure that Sony has shared with us in the orbit of 12%.
It is clear that something is degrading the value of contrast modulation that Samsung’s QLED 8K televisions throw beyond reason. This is probably not the last chapter of this interesting discussion, so we will keep telling you when we have more information. Who knows, maybe the next generation of 8K televisions will surprise us.