Samsung S90H / S92H (QD-OLED) vs LG OLED C6H (TANDEM OLED)

The Samsung S90H is a truly bright TV for the midrange among OLEDs. In synthetic measurements its peak brightness reached about 1650 nits. That's an outstanding result in this class, roughly 50% higher than what we’ve seen from previous models at this price point. Crucially, these tests translate directly to real video material. In 4 out of 5 film shots we tested the S90H’s brightness hovered around 1300–1500 nits. That headroom lets the TV reproduce most HDR movies with the same dynamics and expression the creators intended in post-production. Of course, on full-screen, very bright scenes the result is naturally lower and drops to around 900 nits. That’s a direct result of the protection systems that prevent the OLED panel from being overloaded. Even in that scenario there’s no reason to complain. Those 900 nits across the entire screen is still a very high level, ensuring excellent dynamics in HDR content.

A major advantage of QD-OLED TVs has always been color, and the S90H is no exception. The DCI-P3 gamut we measured reached a full 100% (exactly 99.9%), while coverage of the much wider BT.2020 gamut hit roughly 89%. That’s a great result, allowing you to enjoy extremely saturated, vivid colors in HDR content. It’s worth noting these figures are better than WOLED panels, which is especially noticeable in very demanding film scenes.

And it's with HDR that the Tandem OLED panel shows its biggest advantage. The C6H's brightness is simply very high and in our measurements it hovered around 1900–2300 nits in most movie scenes. That's already a level at which bright highlights, the sun, or small light sources can look truly spectacular. The biggest impression on us, however, was the fifth scene from the film The Meg. It is exceptionally demanding for OLEDs because practically the entire screen is very bright. Even so, the C6H reached about 1650 nits there. For comparison, the regular C6 with a classic WOLED panel delivered around 600–700 nits in the same spot. So we're talking about more than double the brightness, and in places the difference approaches threefold. That is probably the best example of what Tandem OLED brings. It's not just a higher result on a small test patch. The C6H can sustain very high brightness even when much more of the screen is lit. Thanks to that, HDR has a significantly greater dynamic range and in this respect the C6H is much closer to flagship OLEDs than to typical mid-range models.

Colors

Tandem OLED also brings improvements in color. DCI-P3 coverage remains practically full at about 99%, while in the much wider BT.2020 gamut we measured roughly 82–83%. That's about 7 percentage points more than the regular C6. In everyday use this won't be a visible difference in every scene, since most films don't use such a wide gamut. However, when very heavily saturated colors appear, the C6H already has noticeably greater capabilities, especially in reds. Reds benefit the most, becoming deeper and more saturated. It's still not at the level of the best QD-OLED panels or SQD TVs, but for a WOLED panel the result is really very good.

The next stage of the test was to check how the S90H handles color reproduction without any calibration. As always, we took measurements in Filmmaker Mode, the best out-of-the-box picture setting. And here Samsung truly deserves praise. The factory tuning is at a very high level, and a few years ago that wasn't one of its strong points. The white balance was set correctly, as was the brightness response. The average color error (Delta E) hovered around 3, which is below the level at which most people can notice inaccuracies. Only in the brightest shades of gray did values slightly approach 4, but it's still hard to consider that a real viewing issue. For settings straight out of the box, the result is simply excellent.

Right out of the box the LG C6 is pretty well calibrated, especially if you select Filmmaker mode. In SDR content the white balance is quite good, although as brightness increases it starts to show a slight lack of red. The picture becomes a bit cooler as a result, but not enough to be very noticeable during normal viewing. More is happening in the luminance response. Gamma is a bit low and, instead of holding at 2.4, it sits closer to 2.1–2.2 across much of the range. In practice the C6 slightly brightens the midtones. Shadows are therefore more readable, but the image loses some depth compared with how it should look in a dark room.

The situation is a bit more interesting in HDR. The start of the grayscale looks very good, but from roughly 20–30% brightness the white balance begins to drift increasingly. As brightness rises, red increases and blue becomes noticeably lacking. In the brightest areas the difference is already substantial and also affects the reproduction of some colors. The EOTF curve itself is, however, fairly well followed over most of the range. The C6 only tends to slightly brighten the image, which we also saw during our film comparisons. The largest deviation appears around the brightest sections, where the TV begins to map the signal to the panel’s capabilities.

The out-of-the-box Filmmaker mode in HDR is therefore not perfect, but overall it performs well. The biggest room for improvement is the white balance, especially at high brightness.

Okay, but you know we wouldn’t be ourselves if we didn’t check how much more we could squeeze out of the S90H with professional calibration. And there was no big surprise here: since the out-of-the-box settings were already very good, there wasn’t a huge reserve. Even so, we managed to refine the picture almost to perfection. After calibration the average color reproduction errors fell below the threshold of perception, reaching Delta E values under 2 for both SDR and HDR material. We also improved the brightness response, so the image more faithfully reflects the creators’ intent and maintains proper tonality across the full brightness range. Not necessarily, because the factory settings already deliver a very high level. If you want the most accurate image and want to squeeze absolutely everything out of this panel, the S90H offers that potential. After professional calibration it’s simply an almost reference display.

Will the difference be spectacular for everyone? Not necessarily. It depends a lot on the individual unit. Our sample was very well tuned straight out of the box, but that doesn’t mean every S90H will perform at the same level. Even identical models can vary in their factory calibration. That’s exactly why professional calibration makes sense: it lets you bring a specific unit to the highest possible accuracy instead of hoping for a bit of luck when buying.

LG TVs have been very receptive to calibration for years, and the C6 is no exception. After correction we were able to set the white balance almost perfectly, and most color errors (Delta E) fell below 3, often even around 2. In practice this means very accurate color reproduction in both SDR and HDR. The only curiosity showed up with the HDR luminance response. On the standard EOTF chart everything looks nearly perfect and at first glance it would be hard to fault anything. Only when we measured the TV’s behavior using filters based on actual movie scenes did it become apparent that the C6 has a slight tendency to artificially boost image brightness.

It’s not a huge difference and many people may even take it as a positive, since HDR looks a bit more striking because of it. From the perspective of fidelity to the source material, however, this isn’t ideal — some scenes are simply a bit brighter than the filmmaker intended. Interestingly, this is rather atypical for LG. In previous generations LG TVs usually adhered closely to the reference picture curve after calibration. With the C6 we’re still very close to the standard, but that subtle brightness "boost" can indeed be noticed in movies and TV shows.

In this regard Samsung has practically changed nothing compared with last year’s model, which is actually pretty good news. The function responsible for smoothing tonal transitions still very effectively reduces posterization. You should remember, however, that it works quite aggressively, because besides removing artifacts it can also eliminate film grain and slightly soften fine image details. As always, it’s a matter of compromise and personal preference. If you want the most faithful reproduction of the source, we recommend leaving this function turned off.

There’s also no revolution when it comes to upscaling. The S90H uses the same proprietary NQ4 Gen3 image processor as its predecessor, so scaling quality has remained virtually unchanged. The TV handles lower-resolution content well, effectively improving sharpness. The overscan issue still hasn’t been solved, though. With some older material, especially archival footage, parts of the image at the edges may be cropped. It’s a minor flaw, but it’s a shame Samsung left this problem unchanged for another year running.

Here the LG C6 has taken a really big step forward. The TV uses the same processor found in the flagship G6, and in terms of image processing the two models are very similar. That's a big plus, because in this area LG's processor this year performs excellently. The "Smooth Gradation" feature works especially well. With heavily compressed material it can effectively hide ugly banding and artifacts that often appear, for example, in lower-quality streaming. It's best to leave it on the "Low" setting. That way the improvement is noticeable, and the TV doesn't yet start blurring fine details. Higher levels smooth the image more, but can start to remove some of the natural texture of objects on screen. The upscaling itself also performs very well. Lower-resolution material is properly sharpened, edges look clean, and the processor quite effectively reconstructs fine details. In this respect the C6 is already very close to LG's best TVs, and the differences compared with the G6 are small.

In terms of motion smoothness, the S90H delivers a very high level. New here is a panel with a 165 Hz refresh rate. In practice, when watching movies or sports broadcasts it's hard to notice any difference, because that kind of content doesn't use refresh rates higher than 120 Hz. The extra 165 Hz will be appreciated mainly by PC gamers who can generate that many frames per second. Samsung equipped the TV with advanced motion settings. You get two sliders (judder reduction and blur reduction) that make it easy to tailor the picture's character to your preferences. You can easily get very smooth motion for sports, but you can just as easily preserve a more cinematic feel with the typical 24 fps. It all depends on which effect you prefer.

The C6H with a Tandem OLED panel can also operate at refresh rates up to 165 Hz. PC gamers will get the most use out of that, of course, because for consoles, movies, or sports we’re still talking about a maximum of 120 Hz. The panel itself performs excellently in motion. OLED pixels respond virtually instantly, so even with fast-moving objects you don’t see the typical motion blur behind them. The image stays clean whether you’re watching sports or playing fast-paced games.

If you care more about smoothness than motion clarity, TruMotion is available. LG lets you adjust two parameters separately. De-Judder works mainly with films and series shot at 24 fps and helps reduce the judder typical of them. De-Blur, on the other hand, is intended for 50/60 fps material, so it’s especially useful when watching sports or TV.

From the start the Samsung S90H feels like a TV designed with gamers in mind, and honestly... it's hard to blame them. The manufacturer equipped it with everything you’d expect from a gaming TV. You get four full-bandwidth HDMI 2.1 ports, support for ALLM and VRR, and very high refresh rates. There’s also a clear Game Bar that lets you quickly check key picture parameters or change settings without leaving the game. Another very welcome improvement is that HGiG now works properly. Last year it could cause a lot of issues, but on the S90H it behaves exactly as it should.

Samsung’s real ace, however, is its proprietary Game Motion Plus mode. The feature works similarly to the motion smoothing known from movies, improving animation smoothness in games while keeping input lag at a very reasonable level. For titles running at 30/60 fps, with the right settings, input lag did not exceed 40 ms in our tests. That’s a very good result, especially since enabling similar features from many manufacturers can end up increasing lag three to four times. It’s a feature that partly makes up for the lack of Dolby Vision Gaming. A smoother image often provides more noticeable benefits than the HDR format itself, so for many gamers this will be a far more valuable addition.

The C6H offers basically a full package of gaming features. On consoles we can easily use 4K at 120 Hz, while PC users can push the refresh rate up to 165 Hz. The TV also supports VRR from 40 to 165 Hz, ALLM and a proper implementation of HGiG. Dolby Vision is also available in game mode, which remains a significant advantage for Xbox owners. We can view all the key information in the Game Bar, which provides quick access to VRR settings and current signal parameters. The OLED tandem therefore doesn't change the actual feature set for gamers, but with such high panel brightness HDR games can make an even bigger impression. Functionally, the C6H is simply a very complete TV for console and PC.