LG предупреждает о реальных 8K против поддельных телевизоров 8K
https://www.gadgetguy.com.au/lg-warns-o ... isplay=allhttps://www.flatpanelshd.com/news.php?s ... 1567494878LG set up an interesting comparison demo at IFA 2019, demonstrating the "Real 8K" resolution of the company's NanoCell 8K TV based on contrast modulation (CM) measurements.
Contrast modulation generally refers to the ratio between the luminance of white over the luminance of black on a 1x1 grille pattern, to determine how clear adjacent single pixels can appear distinct to the eye.
The LG Nanocell 8K TV achieved a CM figure of 90%, whereas a rival 8K TV (likely a Samsung 8K QLED based on the subpixel structure and dithering pattern) only reached 12%.
Earlier this month, LG issued a press release announcing that its new 8K OLED and Nanocell TVs deliver "real 8K" resolution as defined by established display industry standards.
пример
The Korean company is using the ICDM definition as a tool in its marketing but there is merit behind the claim. FlatpanelsHD has examined the effects of sub-pixel rendering / dithering, which is employed in Samsung's latest 8K and 4K "QLED" LCD TVs. See our review of Samsung Q90R and our further examination of Samsung's 8K TV here.
https://www.flatpanelshd.com/news.php?s ... 1567494878Notice how shadows and areas around the hairline pixellate. Here, the effective resolution is lower than 8K.
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In the other example, you can see how it works. Pixels are controlled in clusters of four. With this shade of green, only one pixel is lit, while the three other pixels are either dimmed down or turned off. In the worst case scenario, you get 4K resolution but this will require special test patterns. With real content, you are more likely to see effective resolution somewhere between 4K and 8K.
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As you may have guessed, sub-pixel rending does have drawbacks, with the main one being lower effective resolution when the wide viewing angle system is active. When examining the pixel structure more closely, we found that the LCD panel has a gate pattern that negatively affects picture details.
The photo to the right illustrates the same picture section from Samsung Q90R and Sony A9F, revealing that you some of the finer details (i.e. the pupil) in the picture are lost, and that color gradients or contrast transitions (around the hair) appear with dithering artefacts.
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Samsung_Q90R_Sony_AF9_05.jpg (216.75 КБ) Просмотров: 2925
"For a “real 8K” experience, pixels must be easily distinguishable from one another. According to the ICDM, Contrast Modulation (CM), which measures precisely if neighbouring pixels are distinguishable from one another- is the relevant way to measure and describe display resolution.
For any TV display to deliver the resolution indicated by its pixel count, the ICDM requires the minimum CM value to exceed a threshold of 25% for images and 50% for text. An 8K TV with a CM value that is lower than these required thresholds does not deliver real 8K, even though the TV may in fact have the sufficient number (7,680 x 4,320) of pixels"
Using as few as one-in-four pixels for 25% brightness will result in having lower CM values. Turning off pixels versus dimming them is a much lower-cost way to lower brightness at the expense of detail, HDR and colour. The customer is not getting a true 8K image nor brightness.
Samsung's Q900R is using one-in-four pixels producing a fly-screen effect. When you know what to look for the flyscreen effect – pixelation – becomes obvious as a much softer focus in dimmer areas and a loss of HDR detail.
Οne in four pixels turned off – notice fly screen effect in Samsung Q900R 8K
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All pixels on using active dimming to 25% in LG 8K Nano panel
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The left picture illustrates the quality if pixels are dimmed. The right illustrates the ‘holes’ if they are turned off leading to lower resolution
CM.jpg (80.57 КБ) Просмотров: 2925