LG OLED G5 vs LG OLED C6H (TANDEM OLED)

LG G5 with the new Tandem OLED panel brings the biggest change specifically in terms of the brightness of the television. And it’s quite impressive. This is truly an astronomically bright OLED. In every tested scene – whether it’s point lights or full-screen whites from the movie 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 comes close, and at times even surpasses the best Mini-LEDs on the market. A new feature of the Tandem OLED panel is the expanded color gamut coverage – and here the LG G5 performs almost perfectly. DCI-P3 achieves a full 100%, while BT.2020 maintains 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 color saturation. This is an OLED that can truly shine – and not just figuratively.

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.

Our test unit LG G5 struggled with some issues in the factory Filmmaker mode. And while the image might have seemed fine to most people, we knew that this TV was capable of much more. This mode had a clear excess blue tint in the white balance, resulting in a strong cooling of the image – particularly in HDR modes, where there was also a lack of red. The picture seemed cold, and its sharpness was artificially boosted and unnatural. Another significant issue was the brightness characteristic. 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, and larger, bright elements appeared overexposed and lacking gradation. Luckily, the G5 supports calibration using 3D LUT (a tool for professionals to calibrate colors), so we decided to take advantage of its professional background 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 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 completing 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 the value of 2, which is a phenomenal result, practically imperceptible to the human eye. And while one could still criticize that in HDR films the television tends to slightly dim the smallest elements of the image, in practice, this does not negatively affect the overall impression. Hats off to LG, because once again they provide the user with enormous possibilities for adjusting their display – and this, combined with very good parameters of the panel itself, results in an image that is truly hard to surpass.

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.

Upscaling and digital image processing in the LG G5 perform very well. The television handles lower quality content exceptionally, 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 desired details, such as the subtle texture of clothing or skin, but importantly – it does not remove film grain, so it’s hard to say there’s a serious compromise here. It’s one of those options that’s definitely worth enabling.

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 edging was visible, but that’s an effect that can’t be completely avoided. Additionally, there were no issues with overscan, 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" 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.

The motion fluidity on the LG G5 is simply phenomenal. The TV is equipped with a 165 Hz refresh rate panel, and this combined with the instantaneous response time of the OLED matrix delivers incredible results. The picture doesn’t stutter or smear like on classic LCD TVs. Like most LG models, the G5 features a motion smoother, which can be useful when watching movies – of course, we're talking about the TruMotion mode. With the “De-Blur” and “De-Judder” sliders, we can adjust the smoothness of older material according to our preferences, whether we want to preserve the characteristic film stutter or move towards a more fluid, television-like effect.

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.

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

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.