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

And the biggest advantage of the Tandem OLED panel is most obvious with HDR. The C6H's brightness is simply very high and, in our measurements across most film scenes, hovered around 1,900 to 2,300 nits. That's the kind of level at which bright highlights, the sun or small light sources can look truly spectacular. The scene that impressed us most was the fifth scene from the film The Meg. It's particularly demanding for OLEDs because almost the entire screen is extremely bright. Even so, the C6H reached about 1,650 nits in that scene. By comparison, the standard C6 with a classic WOLED panel managed roughly 600 to 700 nits at the same point. So we're talking about more than double the brightness, and in places the difference approaches three times as much. And that's probably the best example of what Tandem OLED delivers. It's not just a higher score on a small test window. The C6H can maintain very high brightness even when much more of the screen is illuminated. That gives HDR a much wider dynamic range, and in this respect the C6H is considerably closer to flagship OLEDs than to typical mid-range models.

Colours

Tandem OLED also brings improvements in colour. DCI-P3 coverage remains virtually complete at around 99%, while in the much wider BT.2020 colour space we measured about 82–83%. That's roughly 7 percentage points more than the standard C6. In everyday viewing this won't be a difference you notice in every scene, because most films don't use such a wide palette. However, when very highly saturated colours appear, the C6H has noticeably greater capability, especially with 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 much 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 dynamics, is closer to good SDR than to what brighter models show. That doesn't mean the P7L completely fails at HDR; the issue is mainly a lack of sufficient backlight power. Looking at colours, the situation is a bit better. The TV covers roughly 91% of the DCI‑P3 gamut and about 68% of the wide BT.2020 space, so for its price class the colour range is quite decent. TCL markets this model as QLED, although the nature of the solution used is closer to a PFS phosphor‑based backlight than a classic quantum dot layer. What matters most to the viewer is the effect: more saturated colours are on offer.

Right out of the box the LG C6 is pretty well set up, especially if you select Filmmaker mode. In SDR content the white balance is good, although as brightness increases it starts to lack red slightly. This makes the picture a bit cooler, but not enough to be very noticeable during normal viewing. More is going on 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 a large part of the range. In practice the C6 slightly brightens midtones. Shadows are therefore more readable, but the image loses a little depth compared with how it should look in a dark room.

In HDR the situation is a bit more interesting. The start of the grayscale looks very good, but from around 20–30% brightness the white balance starts to drift more strongly. As brightness increases red builds up and blue becomes noticeably lacking. In the brightest parts the difference is already significant and also affects the reproduction of some colours. The EOTF curve itself is handled quite well across most of the range. The C6 only has a tendency to slightly brighten the picture, which we've already seen in our film comparisons. The biggest deviation appears around the brightest sections where the TV starts to adapt the signal to the panel's capabilities.

So the factory Filmmaker setting in HDR is not perfect, but overall performs well. The biggest room for improvement is the white balance, especially at high brightness.

In Film mode the TCL P7L performs quite decently without major tweaks, especially with ordinary SDR material. The white balance is relatively even, although as brightness increases there’s a slight rise in red and blue and a bit too little green. That doesn’t create a strongly visible colour cast and most colours remain close to their reference points. The Colour Checker confirms this, with a large portion of errors falling below the level that should particularly bother during normal viewing. We have more remarks about the gamma response. In the darkest parts of the image the TV drives it noticeably above the reference, so some shadow detail may be a little too dim. The curve then settles and for much of the range it’s close to the intended targets. As a result SDR generally looks natural, but in dark scenes the P7L can lose some subtlety.

In HDR the factory setup is less precise. As brightness increases the excess blue becomes more pronounced, so the picture can look cooler than it should. The number of larger colour deviations also rises, especially in brighter colours. The EOTF curve itself is handled fairly conservatively, with the TV showing the image darker than the reference over much of the range. For such an inexpensive model, the factory Film mode settings are not bad.

LG TVs have long responded very well to calibration, and the C6 is no exception. After adjustment, the white balance was set almost perfectly, and most colour errors fell to values below 3, often around 2. In practice this means very accurate colour reproduction in both SDR and HDR. An interesting detail only showed up with the HDR luminance response. On a classic EOTF chart everything looks almost perfect and at first glance it would be hard to fault. Only when we measured the TV’s behaviour using filters based on real film scenes did it emerge that the C6 has a slight tendency to artificially boost image brightness.

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

After calibration the TCL P7L can produce a genuinely pleasant picture, especially with conventional SDR material. We managed to even out the white balance very well, and the gamma curve now tracks close to the target value of 2.4. This is also evident in the colour measurements, as most errors have fallen significantly and in everyday viewing it’s hard to notice any major inaccuracies. Films, series, YouTube and regular TV therefore look more natural, without unnecessary warmth or a cool tint. For a model at this price point the SDR result is really very good.

In HDR the situation becomes more complicated. Calibration improved the white balance and corrected some deviations, but here the panel’s limitations become increasingly apparent. The P7L has relatively limited brightness and can’t sustain appropriate luminance for more saturated colours, so some errors remain even after careful tuning. In other words, settings can improve how the TV interprets the signal, but you can’t overcome its physical capabilities. That’s why calibration is most worthwhile for SDR on this model.

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' function works especially well. With heavily compressed material it can effectively hide unsightly tonal banding and artefacts that often appear, for example, in lower-quality streaming. It's best left on the 'Low' setting. That way the improvement is clear, and the TV doesn't yet start to blur fine details. Higher levels smooth the picture more, but can begin to remove some of the natural texture of objects on screen. Upscaling itself also performs very well. Lower-resolution content is properly sharpened, edges look clean, and the processor quite effectively reconstructs fine details. In this respect the C6 is already really close to LG's top TVs and the differences compared with the G6 are small.

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

The upscaling itself also looks good. Lower-resolution material is upscaled properly, without excessive sharpening or adding artificial edges around objects. Of course the P7L won't turn a very poor source into a 4K-quality picture, but for regular TV the result is simply solid. For a model at this price point there are few major complaints to make.

The C6H with a Tandem OLED panel can also run at a refresh rate of up to 165 Hz. PC gamers will get the most out of that, of course, because with consoles, films or sport we're still looking at a maximum of 120 Hz. The panel itself performs excellently in motion. OLED pixels respond almost instantly, so even with fast-moving objects you don't see the usual trailing. The picture stays clean both when watching sport and in fast-paced games.

If you prioritise smoothness over motion clarity, TruMotion is available. LG lets you adjust two parameters separately. De-Judder mainly works with films and series shot at 24 fps and reduces their characteristic judder. De-Blur is intended for 50/60 fps content, so it's mainly useful when watching sport or TV.

TCL P7L uses a native 60 Hz panel 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 noticeable judder, but it doesn't deliver the smoothness typical of true 120 Hz panels.

The C6H offers virtually a full gaming feature set. On consoles you 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 correct implementation of HGiG. Dolby Vision is available in game mode too, which remains a big plus for Xbox owners. All the key info can be seen in the Game Bar, which provides quick access to VRR settings and the current signal parameters. The tandem OLED doesn’t change the actual feature set for gamers, but with such high panel brightness HDR games can look even more impressive. Functionally, the C6H is simply a very complete TV for consoles and PC.

For such an inexpensive TV, the P7L has quite a lot to offer gamers. It has ALLM, VRR and Dolby Vision in games, and TCL also includes its Game Bar, where you can quickly check 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 part comes when you give up 4K. At that resolution the TV runs at up to 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 the difference in smoothness is genuinely noticeable, 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. Still, it's precisely these extra modes that make the P7L perform really well for gaming.