Samsung S90H (WOLED) vs LG OLED C6H (TANDEM OLED)

The Samsung S90H in the WOLED variant is still an exceptionally bright TV for its price class, although it is slightly dimmer compared to the QD-OLED version. The difference is not as pronounced as in last year’s F series, where gaps could reach as much as 500 nits. Here the specs of both panels are very close, and differences in peak brightness are only about 100–150 nits. In small-area measurements, the S90H on the WOLED panel easily reaches levels close to 1500 nits. That headroom lets it portray HDR dynamics phenomenally—specular highlights, reflections or explosions have the right punch, just as the creators intended in the post-production studio. As with most OLED displays, when a very bright scene fills the entire screen, the protection systems that safeguard the panel kick in and brightness naturally falls to around 700 nits. It’s worth stressing that this is still an excellent result on the market, often noticeably better than many Mini LED screens in the same segment.

Color gamut coverage

The biggest difference between the two S90H variants lies in color reproduction and saturation. This stems directly from the different construction of the WOLED panel, which uses an additional white subpixel. As a result, colors at very high brightness don’t achieve quite the same intensity, and the volume of the wide color gamut is somewhat more limited than with QD-OLED. That said, in everyday use these differences will be hard for most viewers to notice. Our measured DCI-P3 coverage on the WOLED panel reaches nearly 99%, which means that in the vast majority of real film scenes both variants will deliver almost identical images. The true gap only appears in rarer, particularly demanding productions that use the ultra-wide BT.2020 gamut. Due to the WOLED panel’s design, coverage of that standard is about 15% lower compared to the S90HAT with a QD-OLED panel, so the brightest, heavily illuminated HDR colors may appear a bit less vivid.

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.

In Filmmaker mode, which we strongly recommend enabling right out of the box, the S90H offers very good factory color tuning. Colors are natural and faithful to the filmmakers' intent, without the intrusive oversaturation found in more aggressive profiles. However, as is usually the case without full calibration, there can be unit-to-unit variation. In our test the white balance lacked a bit of the blue component, causing the image to lean slightly toward warmer, yellowish tones. This was most noticeable in bright scenes, such as the snowy sequences from Star Wars. Additionally, the gamma curve ran slightly low, around 2.2, which resulted in a slight boost to shadow detail. In HDR mode the tuning was a bit better, showing only a slight undersaturation in the red region.

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.

After full calibration it can safely be said that the S90H in the WOLED version looks almost perfect. In SDR mode color reproduction errors drop to ultra-low levels, and Delta E values very rarely exceed 2. That's a phenomenal result, so if you care about perfectly faithful color reproduction it's definitely worth considering calibration. The calibrated HDR mode also performs very well, in which the white balance was stabilized and earlier deviations eliminated. After professional tuning it's really hard to find anything to criticize, because the TV delivers an image with almost exemplary naturalness and dimensionality. The slightly lower rating in this category compared with the QD-OLED variant is solely due to the previously described saturation limitation in extremely bright scenes; the tuning options and color fidelity themselves are at the highest level.

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.

When it comes to reducing posterization, Samsung has kept the same solutions as last year’s models. The dedicated gradient-smoothing function works quite well and can effectively mask unwanted tonal transitions, which can be useful on a WOLED panel that is somewhat prone to banding. However, keep in mind it acts aggressively. This mechanism, aside from removing artifacts, can clean up fine film grain and slightly soften detail. Ultimately it’s a matter of compromise, but if you care about an absolutely faithful reproduction, it’s safer to leave this option off.

There’s also no breakthrough in scaling. The S90H uses the same NQ4 Gen3 processor as its predecessor, so the quality of upscaling was almost identical. The chip sharpens lower-resolution material very well, extracting a satisfying level of detail. Samsung still hasn’t dealt with the old overscan issue. With some older recordings or archival material the image edges can be slightly cropped. It’s a minor flaw, but it’s a shame the manufacturer still hasn’t eliminated it.

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 handling, the S90H is simply excellent. This year's panel offers a refresh rate boosted to 165 Hz, though in practice the benefit will be realized mainly by gamers connecting a powerful PC. For movies, TV series, or sports broadcasts, such a high refresh rate makes no difference and the picture looks exactly the same as at the standard 120 Hz. Regardless of the source, the OLED panel's lightning-fast response time does its job, so motion is clean and the ghosting or smearing seen on LCD screens simply doesn't occur here.

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.

Players should feel at home with the S90H, because in that respect Samsung left few reasons to complain. The TV has four HDMI 2.1 ports, each of which supports VRR, ALLM, and high refresh rates. There's also the Game Bar, a handy menu that lets you quickly check key parameters and change settings without leaving the game. Importantly, Samsung has also improved HGiG. In last year's models it could cause issues when used with a console, but in the S90H it now works as it should. What sets it apart from the competition is primarily Game Motion Plus. It's a special motion-smoothing mode designed for games, which works best with titles running at 30 or 60 frames per second. Motion becomes noticeably smoother, while latency remains at a reasonable level. In our measurements it was under 50 ms, so you can still play comfortably. That's important, because on many TVs turning on a similar smoothing mode causes such a large increase in input lag that controls start to feel noticeably sluggish. Samsung has managed to find a good compromise here. There's still no Dolby Vision Gaming, but in practice Game Motion Plus may prove to be a far more useful feature.

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.