QLED Versus OLED, What To Expect From Samsung’s 4K And 8K TVs

Earlier this week, Samsung announced their new 2019 lineup of 4K and 8K televisions using a display technology they call QLED. The term QLED looks suspiciously like OLED, but do the two technologies actually have much in common? After fielding a few questions about this on our website and social media, we want to clear up any confusion between them and expound on what to expect in terms of picture quality from each.

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We will start at the beginning with a basic LED LCD display. Virtually everyone has encountered one of these displays at some point in their life as they make up the majority of the market. These use a white LED backlight to shine through tiny red, green, and blue filters to create the image we see. The filters can be opened and closed on demand and to varying extents thanks to liquid crystals -- the LC in LCD. Older non-LED LCD displays worked in similar manner, only they employed cold-cathode fluorescent lamp (CCFL) backlights instead which were bulkier and more expensive to produce.

There are, of course, a number of shortcomings with traditional LED LCD displays. For one, these displays are prone to light "bleeding" through closed filters, resulting in blacks that are more of a glowing dark gray. Even when displaying an all-black image, the screen still glows more than it would if the display were powered off. The LED backlighting can also be inconsistent across the panel which is most noticeable in dark scenes.

Another issue stems from LED technology itself: pure white LEDs do not really exist. A true white light would contain the full spectrum of frequencies and produce a rainbow when shown through a prism. LEDs are much more limited in the frequencies they produce. To get "white" LEDs for the backlight, manufacturers start with a blue LED and apply a yellowing phosphor-coat to warm up the light to a neutral white.

This pseudo-white light is still deficient in certain wavelengths -- particularly reds. The impact here is that the resulting brightness of the display has to be tempered to the peak brightness of the dullest color for best results. This further reduces the amount of color space a display can reproduce. Keep in mind, both display brightness and color space are major components of HDR display certification.

lg oled technology
OLED TV Technology

OLED displays by contrast -- no pun intended -- do not need a blacklight because the individual sub-pixels are emissive. OLED panels can directly produce the red, green, and blue light needed to produce an image by independently varying the brightness of each. Additionally, individual sub-pixels can be shut off entirely for truer blacks than LED LCD displays can produce.

We will note that some OLED variants, including LG's, work differently by stacking the red, green, and blue sub-pixel layers to produce a white light that is then filtered back to red, green, or blue like and LCD display. These displays are often dubbed WRGB as in "white, red, green, and blue". Compared to blue-yellow LED LCD displays, the white light produced by a WRGB OLED covers more of the spectrum and retains better color after being filtered while also retaining the ability to selectively turn off pixels. The subpixel stacking also virtually eliminates the effects of pixel burn-out OLEDs face with static images because all the pixels wear at the same rate regardless of color.

OLED has been the gold standard for television displays for a few years now thanks to its impressive image quality, but remains expensive to produce for large panels and peak brightness still lags behind LED displays. To shore up LED's weaknesses, Samsung has been investing heavily into QLED technologies.

samsung qled up close
Samsung QLED TV Up Close

QLED is better known as Quantum Dot, but the term Quantum Dot gets us no closer to understanding how it works. Quantum Dots are in fact tiny nano-scale particles that can be excited by light to emit their own light. The wavelength of this light is very precise and depends upon the Quantum Dot's physical characteristics. In effect, manufacturers can create a display with a uniform backlight and use Quantum Dots in the sub-pixels to create red, green, and blue independently. Making matters simpler, a blue LED can serve as the backlight and be used unfiltered for blue sub-pixels while also exciting red and green Quantum Dots as needed for their corresponding sub-pixels, all while covering color space comparable to OLED displays.

To OLED Or QLED - That Is The Question

So, are the newest QLED offerings good enough to dethrone OLED? It is certainly going to depend on how you watch your television. Let's break things down into a few categories: brightness, black levels, viewing angles, response time, power efficiency, longevity, and price.

As alluded to earlier, OLED panels tend to struggle with brightness output. That is not to say they are dim by any measure, however. The HDR specifications do not point to any particular brightness value to qualify, but the general consensus is around 1,000 nits with a good portion of HDR content being mastered with this level in mind. While OLED panels can meet this threshold, bright pixels do wear faster, but more on that later. QLED panels, on the other hand, are able to produce tremendously bright pictures with ease. Samsung's new Q900R, for instance, claims a peak brightness of 4,000 nits.

Conversely, OLED panels are unmatched for black levels. Samsung has made improvements to their QLED tech including the addition of an anti-reflective layer, but improving the filters to block more backlight still cannot compete with turning pixels off. This advantage really helps OLED TVs pop in dark rooms in a way no backlit solution can.

samsung qled viewing angle

OLED TVs also have the upper-hand with odd viewing angles. Since the OLED pixels are directly emissive, they can be seen from just about any angle without degrading the image. QLED and other LED backlit panels are best viewed dead-on. Off-axis angles reveal a loss of contrast and color shift which tends to worsen the further from center you move. As with black levels, Samsung has made improvements here with their anti-reflective coating to minimize glare so it is at least less of a concern than it used to be.

An often overlooked metric for displays, response times measure how long it takes a pixel to change colors. These response times typically track the time it takes a pixel to turn and off or else from one gray level to another. Faster response times reduce artifacting, ghosting, and motion blur. Once again, OLED takes the crown here, thanks to its individual control over pixels. QLED panels still rely on local dimming which impacts regions of pixels, resulting in a slower response time. We will add that this is a different phenomena than input lag, but input lag varies too much from model to model to really pin down on display technology alone.

samsung qled tv technology

For what it is worth, QLED panels are more environmentally friendly than their OLED competition. Eliminating the need for large backlights seems like it would reduce power consumption on paper, but OLED televisions end up consuming more power to light up pixels individually. The gap does narrow as screen size increases, but for most practical display sizes -- 45" to 65" -- QLED panels are simply more efficient. For example, the 65" Sony Q90R is rated at 115W of typical power draw with a peak of 255W while Sony's 65" A9F OLED TV pulls in a whopping at 500W. Rtings.com also has a handy calculator to estimate consumption differences at various sizes.

Longevity is another area where OLED panels stumble. Make no mistake, modern OLED displays are significantly more resilient than they used to be. Many newer models are rated for tens, if not hundreds, of thousands of hours of continuous operation before dimming down noticeably. HDR content with high peak brightness does have the potential to accelerate this clock, but we do not think it is a serious concern for even the most avid movie fanatics. Regardless, QLED's Quantum Dots are effectively stable over time enough to not degrade in any meaningful way, which gives them the edge here.
samsung qled 8k 2019 television
Finally, it all comes down to cost. Neither is exactly cheap, but Samsung's QLED offerings tend to be a little easier on the wallet. The two 4K 65" models we just covered under power consumption rival used cars at $3499.99 for the Samsung and $4499.99 for the Sony. If 8K is more your style, Samsung also offers a 65" 8K QLED television for $4999.99 and other options ranging up to the behemoth 85" Q900 at a cool 15 grand. Rival 8K OLED televisions from LG and Sony are not quite on the market yet, but we would anticipate them to clock in even higher. In the realm of affordable televisions, Samsung's new 55" 4K Q60R can be had for just $1199.99 while LG offers a comparable 55" OLED B8PUR for $1599.99 currently.

While it looks like OLED retains the picture quality lead for now, do you think Samsung's QLED models are attractive enough to save some cost?
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