These three LG TVS offer inferior RGBW 4K and a weak deal for consumers
Stephan Jukic – September 25, 2016
Buying a 4K TV is now more affordable than ever before and often also includes getting your hands on some truly wonderful name brand ultra HD TV models with great, even premium features at superb prices. Nothing has shown this to be the case more than some of the new TVs we’ve seen emerge in 2015 and 2016 in particular. However, while going for the best possible deal on 4K display is a great idea if you’re working with a limited budget, not all the offerings on the market deliver quite what you might be hoping for.
In the case of select LG TV models, even the basic 4K spec itself, which should be a guaranteed minimum of any TV which is called a 4K set, may not completely apply. Specifically, this is the case with LG’s low-priced 2016 UH6100, UH6400 and UF6800 series television models. Aside from failing to offer the quality and better extra display features of their pricier LG cousins, these particular TVs don’t even deliver truly competition-comparable 4K ultra HD resolution but, LG itself still calls them 4K televisions.
Now don’t get us wrong, LG is one superb UHD TV brand and their OLED 4K TV models are what we consider to be the best consumer televisions of any kind on sale today on the North American market. Furthermore, while we haven’t always liked many of their LCD 4K TVs, the majority of them are decent performers and some such as the UH8500 and UH9500 models are actually quite great performers with excellent HDR color and some beautiful specs. These TVs are all also however much pricier than the 6100, 6400 and UF6800 series TVs.
And this is where the rub lies. The UH6100, UH6400 and UF6800 models all offer lower prices by LG standards but LG’s description of them as real 4K TVs is disingenuous in a way we haven’t seen with the most affordable ultra HD TVs from any other brand on the market. Unlike Samsung’s Sony’s, Vizio’s or other brands’ most basic UHD televisions, these LG models don’t even deliver on their 4K resolution of 3840 x 2160 pixels in the classical sense of the spec. Instead, what they do offer is a sort of pseudo-4K which really consists of 2.8K native full color resolution.
The UH6100, UH6400 and UF6800 series TVs do indeed offer 2160 horizontal scan lines with 3840 pixels in each line but unlike regular real UHD displays, these models pull a sort of trick which reduces image sharpness by substituting red, green and blue subpixels in some of their full pixels for white subpixels. This mechanism is called RGBW and it’s distinctly inferior to the RGB found in real 4K TVs.
Basically, in a normal 4K UHD TV, each of the 8.29 million pixels consists of three subpixels, one for red, one for green and one for blue. Sometimes a white subpixel is also added to these three RGB subpixels for enhanced brightness. This normal 4K display process is called RGB and it’s a key piece of the technology which produces maximal color saturation and gamut in regular and even high end 4K TVs (taking aside even more advanced technologies like HDR).
In the case of the three LG TVs mentioned above however, the RGBW mechanism is used instead and with this, instead of adding a white subpixel to its regular range of RGB subpixels in each of the UH6100, UH6400 and UF6800 TVs, LG completely replaces every fourth red, green or blue subpixel with purely white one in these TVs. As a result, out of every four regular full pixels in the TV display, three are missing whole key colors for quality ultra HD image rendering.
For a clearer idea of what RGBW looks like in comparison to RGB, you can see the comparison between RGB and inferior RGBW in the graphics below:
The result of this manipulation is a picture quality which only offers about 2.8K (2880 RGB) of actual full color pixel resolution with the remaining subpixels totaling up to 1.2K of white substitution. One further highly visible negative effect of the RGBW display and its saturation of white subpixels is a terrible black uniformity and black level performance in all three of these TV models. This is a problem common to many LG 4K LCD TVs but it’s at its very worst in the three RGBW models we’re covering here.
The tricky bit from LG here is that since there are actually 3840 x 2160 pixels on the screen, TVs with RGBW can technically be called 4K models, even if they don’t offer a full 4K worth of full color resolution.
LG accepts that they do this, since they obviously can’t deny what anyone can test with one of these TV displays but the company also defends the practice by saying that it improves luminance and also causes power savings for users of the TVs because instead of having to activate all three RGB pixels to equal brightness to create white light (this is how white is normally created in 4K TVs), they simply depend on the actual white subpixels for white light. The company also claims that the TVs are cheaper to produce and thus more budget friendly for consumers.
All of these points have their validity but the fact remains that these TVs are being marketed as 4K models and in reality they don’t actually produce 4K levels of picture sharpness. Those red, green and blue pixels are crucial to sharp details of content on the TV and the replacement of a full quarter of them with generic white pixels creates exactly the effect you’d get from native 3K resolution (2.8K to be exact). Even if the white pixels are scattered around with no two white pixels ever being next to each other vertically or horizontally the maximum RGB-created color saturation and even resolution of these TVs is ¾ of what it is in a full RGB 4K TV set.
Yes, the UH6100, UH6400 and UF6800 “4K” TVs are being sold for lower prices than those of their full RGB LG 4K cousins (the 50 inch UH6100 and UH6400 models cost about $700 and $750 respectively and the smallest 55 inch UF6800 TV sells on Amazon for $1,500) but they’re still not being sold for reasonably cheap prices at all considering the defects that RGBW produces. Full 4K RGB budget TV models from Sony, Samsung and particularly Vizio can be found at the same or even lower prices while offering true 4K resolution, full RGB subpixels in all 8.29 million full pixels and black performance far better than that of these three LG TVs.
In very basic terms, LG is playing an unfair marketing and display quality game with the consumers who are thinking of buying these TVs or have bought them already.
Story by 4k.com