LG OLED G5 vs LG OLED C6H (TANDEM OLED)

LG G5 with the new Tandem OLED matrix brings the biggest change in terms of the brightness of the television. And it's substantial. This is truly an astronomically bright OLED. In every scene tested – whether it was point lights or full-screen whites from the film The Meg – the 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 new feature of the Tandem OLED matrix is also the expanded colour gamut – and here the LG G5 performs almost perfectly. DCI-P3 reaches a full 100%, and BT.2020 is maintained at around 83%. These are some of the highest values currently available on the market – it's hard to find any other television that comes close to such results, unless we are talking about the best displays with QD-OLED panels. The G5 has nearly reference-quality HDR – both in terms of brightness and colour saturation. This is an OLED that can truly shine – and not just figuratively.

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

Colours

Tandem OLED also brings an improvement in colours. DCI-P3 coverage remains practically complete at about 99%, while in the much wider BT.2020 colour space we measured around 82–83%. That’s roughly seven percentage points more than the regular C6. In everyday use this won’t be a difference visible in every scene, because most films do not use such a wide gamut. However, when very highly saturated colours appear, the C6H already has noticeably greater capability, especially in reds. Reds benefit the most, becoming deeper and more saturated. This still isn’t at the level of the best QD-OLED panels or SQD TVs, but for a WOLED panel the performance is really very good.

Our test unit, the LG G5, struggled with certain issues in the factory Filmmaker mode. And although most people might have found the picture acceptable, we knew that this television was capable of much more. This mode had a clear excess of blue tint in the white balance, resulting in a significantly cooled image – particularly in HDR modes, where there was additionally a lack of red. The picture appeared cold, and its sharpness was artificially boosted and unnatural. Another significant issue was the brightness characteristics. In SDR content, the situation wasn't the worst, aside from a slight dimming of the entire image. However, it performed 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 tool for professionals for colour calibration), so we decided to make use of its professional capabilities and see what it could really do. Because although it wasn't tragic even before calibration, the potential of this television definitely deserved more.

Straight out of the box the LG C6 is fairly well set up, especially if you select the Filmmaker mode. In SDR content the white balance is decent, although as brightness increases it shows a slight deficiency in red. The image therefore becomes a little cooler, but not enough for the difference to be very noticeable during normal viewing. More is happening in the brightness 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 midtones. Shadow detail is therefore more readable, but the picture loses some depth compared with how it should look in a darkened room.

In HDR the situation is a bit more interesting. The lower end of the greyscale performs very well, but from roughly 20–30% brightness the white balance starts to drift increasingly. As brightness rises there is more red, while blue becomes noticeably deficient. In the brightest scenes the difference is already substantial and also affects the reproduction of some colours. The EOTF itself is, however, fairly well tracked across most of the range. The C6 merely tends to slightly brighten the image, which we already saw in our film comparisons. The largest deviation appears in the very brightest areas, where the TV begins to adapt the signal to the panel’s capabilities.

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

After performing the calibration process using professional tools, we can confidently state that the LG G5 offers nearly 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 television still has a tendency to slightly dim the smallest elements of the image, in practice this does not negatively affect the overall impression. Kudos to LG, as once again they provide the user with enormous possibilities for adjusting their display – and this, combined with the very good parameters of the panel itself, results in an image that is truly hard to beat.

LG TVs have long been very receptive to calibration and the C6 is no exception. After adjustment the white balance could be set almost perfectly, and most colour errors fell below 3, often even down to around 2. In practice this means very accurate colour reproduction in both SDR and HDR. An interesting detail only emerged when we looked at the HDR luminance response. On a classic EOTF plot everything looks almost ideal and at first glance it would be hard to find fault. Only when we measured the TV's behaviour on filters based on real film scenes did it become apparent that the C6 has a slight tendency to artificially boost image brightness.

It is not a huge difference and many people may even welcome it because HDR looks a bit more striking as a result. From the point of view of fidelity to the source material this is not ideal behaviour though – some scenes are simply a touch brighter than the filmmaker intended. Interestingly, this is rather unusual for LG. In previous generations the brand's TVs typically stuck closely to the reference picture characteristic after calibration. With the C6 we are still very close to the standard, but this subtle brightness 'boost' can indeed be noticed in films and series.

Upscaling and digital image processing in the LG G5 are quite impressive. The television handles lower quality content very well, especially when the "Smooth Gradation" feature is set to a low level. In this mode, it effectively removes unwanted artifacts and issues with visible tonal transitions. It may also slightly smooth out some desirable details, such as the subtle texture of clothing or skin, but importantly – it does not remove film grain, so it's difficult to speak of a serious compromise here. This is one of those options that is definitely worth enabling.

The G5 also performs well with upscaling, which improves the quality of older materials. The test image with the model looked really solid – slight jaggedness was visible, but that's an effect that cannot be completely avoided. Additionally, there were no problems with overscan, which – contrary to appearances – is not at all 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 considerable plus, because this year's LG processor excels in that area. The "Smooth Gradation" function works particularly well. With heavily compressed footage it can effectively hide ugly banding and artefacts that often occur, for instance in lower-quality streaming. It's best to leave it on the "Low" setting. Then the improvement is noticeable, while the TV does not yet start to blur fine detail. Higher levels smooth the picture more, but can already remove some of the natural texture of objects on screen. Upscaling itself also performs very well. Lower-resolution material is sharpened correctly, edges look clean, and the processor quite effectively reconstructs fine detail. In this respect the C6 is already very close to LG's best 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 165 Hz refresh rate panel, and this, combined with the instant response time of the OLED matrix, delivers incredible results. The image does not tear or stutter like on traditional LCD televisions. Like most LG models, the G5 is equipped with a motion smoother, which can be useful when watching films – we are, of course, referring to the TruMotion mode. 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 stuttering or lean towards a more fluid, television-like effect.

The C6H with a Tandem OLED panel can also operate at refresh rates of up to 165 Hz. PC gamers will naturally get the most out of this, because for consoles, films or sport we're still looking at a maximum of 120 Hz. The panel itself is excellent when it comes to motion. OLED pixels respond virtually instantly, so even with fast-moving objects you don't see the typical motion blur. The picture remains clean whether you're watching sport or playing 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 helps reduce the judder that's characteristic of them. De-Blur, meanwhile, is intended for 50/60 fps content, so it's particularly useful when watching sport or television.

Features for gamers? Perfect. That should be sufficient for you to know what level we are dealing with here. The G5 is a television designed with gamers in mind, so we will find literally everything you could expect from a gaming screen. There is a Game Bar, there is 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 television supports variable refresh rate (VRR), automatic low latency mode (ALLM), and also correctly handles HDR in games thanks to the HGiG function. All of this adds up to one of the best sets of gaming features available on the market. Well done, LG.

The C6H offers practically the full suite of gaming features. 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 proper implementation of HGiG. Dolby Vision is also available in game mode, which remains a major advantage for Xbox owners. All key information can be viewed in the Game Bar, which provides quick access to VRR settings and the current signal’s parameters. The OLED implementation therefore does not alter the feature set available to gamers, but with such high panel brightness HDR games can make an even stronger impression. Functionally, the C6H is simply a very complete TV for console and PC gaming.