OLED 4K TV VS. LCD 4K TV: Your comprehensive comparison across key specs
Stephan Jukic – February 11, 2016
OLED and LED 4K lighting systems cover pretty much all the TV display technologies currently on the market and each have their supporters and detractors. While LCD display lighting technology is found in the vast majority of 4K televisions, a growing range of models offer OLED lighting and the quantity of these is growing each year, with more brands entering the pool as of late 2015.
OLED, which stands for Organic Light Emitting Diode, was originally and primarily the domain of only LG, which released the first consumer-ready OLED 4K TVs in 2014, with several new series coming out in 2015 and now also in 2016. Now, in 2016 Panasonic has also entered this field with its own OLED televisions with ultra HD resolution. LED/LCD TVs (Light Emitting Diode/Liquid Crystal Display) on the other hand are made by every single television manufacturer and represent the older, more affordable and well tested type of TV lighting technology, which relies on large LEDs to illuminate an LCD screen from behind.
One thing that many buyers might ask themselves when comparing TVs with either technology is, which is better in general terms? That’s what we’re going to cover right now. By going through a category by category analysis of how each lighting technology stacks up on various fronts, we’ll come to a final conclusion that you can call our final verdict (at least for now, until new OLED, LCD or other display technologies arrive)
The vast majority of modern 4K TVs are LCD models of some type or another and while they have their different variations, specialized internal innovations and LED lighting array configurations, the basic mechanism by which they function is more or less the same across the board.
In simple terms, LCD TVs depend on different arrays of individual LED lights behind a screen of color filters and liquid crystals which then take the light from those LEDS and either filter or block it (the liquid crystals do this mostly) in order to create a display image in specific color arrangements and lighting configurations depending on the content being shown.
The arrays of light behind the LCD panels and color filters in 4K LCD TVs can vary widely, with the cheapest models offering edge-lit LED backlighting in which along one or more edges of the TV illuminates the screen space horizontally from along the edge. The very cheapest edge-lit LCD/LED TVs offer arrays of LEDs along just a couple sides of the TV rectangle while the most expensive LCD models on the market, like Sony’s X940C HDR TV or Samsung’s top-shelf SUHD models like the JS9500, offer what is called full-array LED backlighting, in which the entire space behind the screen is filled with an array of individual LEDs. The exact number of diodes may vary depending on screen size and TV price but will usually be in the dozens and possibly hundreds.
Local dimming, and its automatic counterpart, local backlighting, is essentially the process by which sections of the screen you see on your TV are dimmed strategically to produce more effective black levels and contrast. Naturally, on an edge-lit LED screen, the process is rather imprecise and the result is often a sort of “Halo” effect around illuminated objects in onscreen content. This Halo effect can be reduced considerably in full-array LED backlit screens since the much larger array of individual LEDs offers a much more precise level of illumination or light cut-off directly behind the LCD panel and onscreen content.
Nonetheless, this is where the key deficiency of LCD/LED comes into play. Regardless of how many individual LEDs and subsequent dimming zones a 4K TV has behind its LCD panel and pixel array in the display, the maximum precision of lighting and black level they can generate across the screen you watch content on is fundamentally limited in comparison to OLED display technology, and now we’ll cover OLED to show you why.
As we just explained in some detail, LCD TVs create illumination and black levels by activating or deactivating LEDs in an array behind an LCD panel that then blocks out or filters their light according to the needs of onscreen content. However, the illumination and light blocking are never absolutely perfect or precise because there are millions of individual screen pixels and the light from the LCDs leaks around large sections of them, even when blocked by LCD technology. Furthermore, the LEDs themselves are large relative to the pixels and cannot perfectly squeeze light into single pixel configurations.
With OLED technology all of the opposite is the case. OLED displays don’t filter LED light through an LCD panel, they instead drive current through millions of individual pixel-sized organic light emitting diodes made of organic carbon and are capable of perfectly shutting off (darkening) or turning them on (illuminating) individually. In really simple terms, While LED/LCD TVs rely on what are in effect tiny light bulbs behind a filter screen, OLED TVs rely on the direct light and darkness of a light emitting surface of tiny carbon diodes in each pixel.
As a result, OLED displays can perfectly control variations of light and dark across every single one of the 8.2 million pixels of a 4K TV display and can also perfectly shut off all light in any visible sense right down to the single pixel level. Furthermore, to generate color, OLED displays either create it within subpixels of red, green and blue colors inside an OLED TV’s pixel array or by using what are called “white OLEDs” in which all three colors are sandwiched together inside a single OLED to create a white light that’s then passed through filters above the OLED layer for different colors in each subpixel.
Furthermore, because OLED TVs don’t depend on LCD screens over LED arrays, they can be ridiculously thin, far thinner than LCD TVs, with the latest LG OLED 4K TV, the G6 having a display that’s only 2.57 millimeters thick!
In a nutshell, OLED technology means a far thinner display thickness, pixel perfect light and black control and perfect viewing angles due to a lack of LCD filters distorting onscreen content during off-center viewing.
Since we covered local dimming and local brightness for LCD screens, the same needs to be covered with OLED, and as you can probably guess from our description of how OLED displays work, local dimming is pixel perfect in an OLED 4K TV. Light in a single pixel can be turned on or off and as a result, blacks are perfect, illuminated objects have no “halo” effect from light bleed around the edges and there are in effect as many local dimming or brightness zones as there are individual pixels in an OLED 4K display, over 8 million of them. No LCD TV can even come close to matching this level of precision today.
The Weigh-in: OLED vs. LCD
Color Rendering and Realism
As exquisite as some of the color rendition technologies we’ve seen in the best LCD TVs on the market are, they simply don’t match OLED in terms of realism and precision. Because each OLED TV pixel contains all the fundamental primary colors needed for producing all the colors of the spectrum, these TVs more realistically reproduce color information in a way that looks simply spectacular in its realism. Yes, we’ve seen LCD TVs with slightly more vibrant and brighter colors due to a mix of quantum dot and phosphor filter technology along with the naturally brighter luminance of LCD (more on that shortly) but if realism is your fundamental measurement of color rendition, OLED wins, hands down so far.
This is one front on which LCD TVs and their LED backlights hare hands down winners. OLED is spectacular but it can’t come close to beating LED in terms of pure brightness, and new innovations in LED light illumination are likely to continue this trend. Furthermore, LED is particularly superior at creating full screen brightness, while OLED does a possibly superior job of illuminating single sections of the screen as far as perception is concerned.
Since OLED is generally dimer than LED backlighting, it’s part of the reason why the UHD Alliance as set different HDR standards for OLED displays, which compensate for their dimmer lighting with a far, far superior level of black, which is essentially perfect in comparison to the light bleed found in even the best LED/LCD blacks. Thus, OLED TVs can create the perception of higher brightness through this superior black level.
Contrast & Black Level
Nothing beats OLED as far as contrast and black level control go. The simple fact that an OLED display can completely turn off all conventionally measurable or in any way visible light right down to the level of a single pixel pretty much ensures an enormous level of performance superiority in comparison to the light bleed that even the very best full-array LED LCD TVs can’t completely avoid. As a result of this perfect, pixel level light and dark control, OLED TVs also offer up exquisite, precisely tuned contrast levels that are great for HDR as long as a lower maximum screen brightness is ignored.
The superior contrast and black level control of OLED and its consequent capacity for superb range of contrast also means an exquisite level of realism in onscreen content, and we can’t not love this.
Nothing so far in LCD technology beats the practically perfect viewing angles of OLED TVs. Because OLED doesn’t require the presence of an extra layer in which LCD TVs have their LCD panel above the illumination source, light, dark and color aren’t distorted in any serious way. Thus, the viewing angles of OLED 4K TVs look nearly perfect even at extreme 80+ degree angles from center. Some OLED 4K TVs do take on a slight yellowish tinge when viewed from this POV but this is a minor inconvenience in comparison to the 50 or more percent of contrast decrease even high quality LCD/LED TVs will show at such viewing angles.
Screen Color Uniformity
The screen uniformity of OLED televisions isn’t perfect, but it comes much closer to being so than what we’ve seen in any LCD TV, even some of the best models from Samsung or Sony. Grey tones and other colors look almost perfect across the screen with only very minor errors in uniformity rarely being visible and usually in older model OLD 4K TVs. In contrast, even high quality generally exquisite 4K LCD TVs like Samsung’s JS9000 show at least some visible lack of uniformity for grey and possibly other colors.
Winner: LCD (tentatively)
Price has always been an issue with OLED TV technology and it applied as a problem of particular concern for consumers who wanted 4K OLED models from LG, which often sold for far more than their premium LCD counterparts. Now however, this disparity between the prices of OLED 4K TVs and top-shelf LCD TVs from other name brands is starting to decrease and while OLED models from 2015 and 2016 still cost a lot, we’ve seen some high-end LCD TVs with inferior display specs which are also only moderately cheaper. Furthermore, there are rumors that LG’s 2016 OLED TV production is going to focus on more affordable mass-market sets, which could finally lead to more reasonable prices across the market for these exceptional TVs.
In terms of raw resolution both LCD and OLED 4K TVs come out equal, and obviously so. 4K UHD resolution is a standardized measurement and will be the same in both: 3840 x 2160 pixels totaling up to about 8.29 million pixels across the whole screen. However –and this is why we even bother to mention resolution—the fact that this feature is the same in both kinds of TVs demonstrates just how secondary pixel count alone is to viewing quality. In light of all the clear and excellent advantages the remaining measurements above give to OLED technology and all pixel counts being equal, resolution alone takes a distant back position as something of importance in the viewing experience.
In a sort of closing summary of general performance, we’d have to give OLED credit over LCD as the superior performer across the board, at least as far as visual specs are concerned. OLED TVs consistently rank as some of the best rated models of 2014, 2015 and likely will continue to enjoy this high opinion in 2016. Their contrast is superb, their light and black control essentially perfect and their color rendition extraordinarily good at reproducing realism on the digital screen. LCD TVs do offer better brightness but the deeper range of blacks in OLED displays also counter this advantage of LCD. With LCD there is also a modest energy savings advantage and better prices but if display quality is the real measure of TV quality then OLED is the king of the current crop of TV technologies.
Story by 4k.com