LG OLED C6H (TANDEM OLED) vs TCL P7L / P79L

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 biggest limitation of the TCL P7L in HDR is simply brightness. The TV doesn't have a large luminance headroom, so strong highlights, sunlight, or small light sources can't clearly "pop" out of the image. As a result, even well-produced HDR material looks fairly restrained and in terms of dynamic range is closer to good SDR than to what brighter models show. That doesn't mean the P7L can't handle HDR at all — the issue is mainly a lack of sufficient backlight power.

Looking at color, the situation is a bit better. The TV covers about 91% of the DCI-P3 gamut and about 68% of the wider BT.2020 color space, so for its price class the color range is quite decent. TCL markets this model as QLED, though the nature of the solution used is closer to a PFS phosphor-based backlight than a classic quantum-dot layer. What matters most to viewers, however, is the result: more saturated colors are available.

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.

In Film mode the TCL P7L performs fairly well without major adjustments, especially with typical SDR material. The white balance is relatively even, although as brightness increases there is a slight rise in red and blue and a bit of a shortage of green. This does not produce a strongly noticeable tint and most colors remain close to their reference points. The ColorChecker confirms this, with a large portion of errors falling below a level that would notably bother viewers during normal watching. We have more concerns about the gamma response. In the darkest parts of the image the TV runs it noticeably above the reference, so some shadow detail can be a little too dimmed. The curve then settles and for much of the range it is close to the intended target. As a result SDR generally looks natural, but in dark scenes the P7L can lose some subtlety. In HDR the factory setting is less precise. As brightness increases an excess of blue becomes more pronounced, making the image look cooler than it should. The number of larger color deviations also grows, particularly in brighter hues. The EOTF curve itself is handled fairly conservatively, with the TV showing the image darker than the reference over a large portion of the range. For a budget model, however, the factory Film mode settings are not bad.

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.

After calibration, the TCL P7L can deliver a really pleasant picture, especially with classic SDR material. We managed to very effectively even out the white balance, and the gamma curve now tracks close to the target value of 2.4. You can also see this in the color measurements, as most errors dropped noticeably, and in everyday viewing it's hard to find any strongly visible inaccuracies. Movies, series, YouTube, or regular TV therefore look more natural, without unnecessary warming or a cool cast. For a model in this price range, the result in SDR is really very good.

With HDR the situation gets more complicated. Calibration helped improve the white balance and tidy up some deviations, but here the panel's limitations become increasingly apparent. The P7L has relatively low brightness and can't maintain appropriate luminance for more saturated colors, so some errors remain even after careful tuning. In other words, settings can improve how the TV interprets the signal, but they can't overcome its physical capabilities. That's why calibration makes the most sense for this model primarily with SDR.

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 this regard the TCL P7L performs surprisingly well, especially for such an inexpensive TV. The tonal transition smoothing feature, which in many budget models does little or almost nothing, actually manages to improve the picture here. It doesn't remove all banding completely, but it can noticeably reduce posterization and make trickier gradients look more natural. At this price point that's a genuinely pleasant surprise.

Upscaling itself also performs well. Lower-resolution material is scaled correctly, without excessive sharpening or adding artificial outlines around objects. Of course the P7L won't turn a very poor source into 4K-quality footage, but for regular TV the result is simply solid. For a model in this class there is little to criticize.

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.

The TCL P7L uses a panel with a native 60 Hz refresh rate at 4K resolution, and that's how it should be treated in everyday use. For movies the TV mainly offers frame interpolation, so it can smooth motion and reduce the typical judder, but it does not deliver the smoothness of true 120 Hz panels.

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.

For such an inexpensive TV, the P7L has quite a lot to offer gamers. It has ALLM, VRR, Dolby Vision for gaming, and TCL adds its Game Bar, which lets you quickly view key information or change some settings without leaving the game. Not everything is perfect, though, because HGiG doesn't work here as it should, but at this price point it's hard to complain much about the feature set. The most interesting thing starts when you give up on 4K. At that resolution the TV runs at a maximum of 60 Hz, but at 1440p and 1080p it can already display at 120 Hz. And that's not just a spec-sheet curiosity. In fast-paced games that support that frame rate you can really notice the difference in smoothness, so if you care more about smoother motion than maximum image sharpness, that mode can make a lot of sense. Of course that doesn't make the P7L a true 120 Hz TV. Even so, it's precisely those extra modes that make the P7L perform really well for gaming.