LG OLED G5 vs LG OLED C6H (TANDEM OLED)

LG G5 with its new Tandem OLED panel brings the biggest change in terms of TV brightness. And it’s substantial. This is a truly astronomically bright OLED. In every scene tested – whether it's point lights or full-screen whites from the movie The Meg – brightness on the G5 exceeded 2000 nits. Just a year ago, such values on an OLED were simply unimaginable. And here we are – the G5 is approaching, and at times even surpassing, the best Mini-LEDs on the market. A novelty in the Tandem OLED panel is also the expanded colour gamut coverage – and here the LG G5 performs almost perfectly. DCI-P3 achieves a full 100%, while BT.2020 hovers around 83%. These are some of the highest values currently available on the market – it's hard to find any other TV that comes close to such results, unless we're talking about the best displays with QD-OLED panels. The G5 has almost reference-level HDR quality – both in terms of brightness and colour saturation. This is an OLED that can truly shine – and not just metaphorically.

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.

Our test unit LG G5 had some issues in the factory Filmmaker mode. While the picture might have seemed fine to most people, we knew this TV could do much more. This mode had a noticeable excess of blue tint in the white balance, resulting in a strongly cooled image – especially in HDR modes, where there was additionally a lack of red. The image appeared cold, and its sharpness was artificially boosted and unnatural. Another significant problem was the brightness characteristics. In SDR content, the situation wasn't the worst, aside from a slight dimming of the entire image. However, it fared much worse in HDR materials – due to improper brightness management, the smallest details could completely disappear from the image, while larger, bright elements looked overexposed and lacking in gradation. Fortunately, the G5 supports calibration using 3D LUT (a professional tool for colour calibration), so we decided to take advantage of its professional capabilities and see what it was really capable of. Because while it wasn't terrible even before calibration, the potential of this TV definitely deserved more.

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.

After completing the calibration process with professional tools, we can confidently state this – the LG G5 offers almost reference-quality image. Most of the errors related to white balance and the ColorChecker test are below a value of 2, which is a phenomenal result, practically imperceptible to the human eye. And while one could still nitpick that in HDR films the TV still has a tendency to slightly dim the smallest elements of the image, in practice this does not negatively affect the overall reception. Hats off to LG, as once again they provide users with enormous display settings options – and this, combined with very good parameters of the panel itself, results in an image that is truly hard to beat.

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.

Upscaling and digital image processing in the LG G5 performs very well. The television handles lower quality content excellently, especially when the "Smooth Gradation" feature is set to a low level. In this mode, it effectively removes undesirable artifacts and issues with visible tonal transitions. It may also slightly smooth out some desirable details, like the subtle texture of clothing or skin, but importantly – it does not remove film grain, so it's hard to talk about a serious compromise here. This is one of those options that is actually worth turning on.

The G5 also does well with upscaling, which is improving the quality of older materials. The test image with the model looked really solid – slight jaggedness was visible, but that's an effect that can't be completely avoided. On the plus side, there were no overscan issues, which – contrary to appearances – is not obvious, even in 2025.

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.

The motion smoothness on the LG G5 is simply phenomenal. The television is equipped with a panel featuring a 165 Hz refresh rate, and this combined with the instantaneous response time of the OLED matrix delivers incredible results. The image doesn’t judder or blur like on traditional LCD televisions. Like most LG models, the G5 comes with a motion smoother, which can be handy when watching movies – we’re talking about the TruMotion mode, of course. With the “De-Blur” and “De-Judder” sliders, we can adjust the smoothness of older materials according to our own preferences, whether we want to maintain the characteristic film jitter or lean towards a more fluid, television-like effect.

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.

Features for gamers? Perfect. That should be enough for you to know what level we’re dealing with here. The G5 is a TV designed for gamers, so you'll find literally everything you might expect from a gaming screen. There's Game Bar, support for high resolutions with high refresh rates - that is, 4K at 120 Hz, and even more, as the panel has a refresh rate of 165 Hz (which PC gamers will benefit from). The TV supports variable refresh rate (VRR), automatic low latency mode (ALLM), and also properly handles HDR in games thanks to the HGiG feature. All of this adds up to one of the best gaming feature sets available on the market. Well done, LG.

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.