LG OLED C6H (TANDEM OLED) vs Sony BRAVIA 2 II (S25M2)

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.

The Sony Bravia 2 II is not a very bright TV and unfortunately that is immediately apparent in HDR. In our measurements brightness stayed around 300 to 330 nits, which is clearly too low for the brightest parts of the image to look truly impressive. In practice, HDR here does not differ that much from standard SDR. Bright highlights, the sun or lamps are of course visible, but they lack the intensity you would expect from HDR material. The Bravia 2 II therefore performs much better with standard SDR content, and in that use its limited brightness will be least noticeable.

Colour gamut coverage

The Sony Bravia 2 II is also not impressive in terms of colour. The TV does not use any additional gamut‑expanding filter, such as the quantum dots found in QLED TVs or a PFS phosphor layer. In our measurements coverage of the DCI‑P3 gamut was about 78%, and the very wide BT.2020 roughly 57%. That's definitely too little to talk about truly saturated colours in HDR material. More intense reds, greens or turquoises will simply be less striking than on TVs with an expanded colour gamut. The Bravia 2 II therefore performs much better in the Rec.709 standard, the gamut used for films, series and television in SDR.

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.

The out-of-the-box colour reproduction in Cinema mode was actually quite good, at least for ordinary SDR material. The Bravia 2 II had a slight tendency to boost reds, so some colours shifted to slightly warmer, at times faintly pinkish, tones. However, this wasn’t a major fault and during normal viewing the picture still looked fairly natural. There was a bit more happening with image brightness. Looking at the gamma curve, you can see Sony doesn’t stick perfectly to the reference value. The darkest areas are slightly lifted, while as brightness increases the gamma gradually rises and a larger part of the picture becomes darker than it should. That said, it’s not such a large difference as to be very distracting in everyday viewing. Overall, SDR straight out of the box performs quite respectably.

The situation is considerably worse in HDR. We’ve already mentioned the limited colour gamut, but in addition the Bravia 2 II noticeably manipulates image brightness here. The EOTF curve sits below the reference value for a large part of its range, which means the TV renders most mid and brighter parts of a scene darker than the source material intends. Only towards the very end of the range does the curve flatten out, as the panel reaches the limits of its capabilities. Combined with a peak brightness of around 300 nits, this results in HDR that not only lacks much brightness, but can also simply look too dark.

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.

Calibration did a lot for the Bravia 2 II, particularly with SDR content. Above all, we managed to even out the white balance and tidy up the gamma, which now follows the reference value much more closely. As a result, the image no longer has the previous pink cast, and the brightness across different areas is much better organised. You can also see this in the colour errors, which after calibration fell to a very low level (with slight issues in the most saturated reds). We also partially managed to rein in the Bravia 2 II in HDR, especially in the way the television handles image brightness. However, there is one thing no calibration can fix: the capabilities of the panel itself. A narrow colour gamut means the television is physically unable to reproduce the most saturated colours present in HDR material. On top of that, the low contrast of the IPS panel means darker scenes are veiled by a grey haze, which robs colours of some of their depth. So we can improve how the Bravia 2 II makes use of its capabilities, but unfortunately we cannot overcome the panel's inherent limitations.

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 upscaling on the Bravii 2 II is quite good and, in that respect, the TV matches the standard Sony has set. Lower-resolution content is sensibly upscaled to 4K, and the image is slightly smoothed in the process without excessive edge sharpening. The situation is worse when it comes to improving footage with visible compression artefacts. This is handled by the "Digital Noise Reduction" function, which at the "High" setting can indeed smooth out some unpleasant tonal banding. The problem is that it does this rather aggressively and, along with the imperfections, it also removes a lot of fine detail, including natural film grain. What is more, when there is more motion on screen its effectiveness drops sharply and any improvement is then minimal. For everyday use we therefore tended not to use this function.

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.

Bravia 2 II uses a 60 Hz panel and, given its capabilities, handles motion quite well. However, bear in mind that it is a basic panel and its limitations are already clearly visible, especially during sports. The TV cannot interpolate 50/60 fps material to a higher refresh rate, so it cannot further improve the sharpness of fast-moving objects. For films and series, however, it offers a conventional motion smoothing feature that can reduce the characteristic judder of material shot at 24 fps.

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.

The Bravia 2 II is not a television that lends itself well to gaming, and the list of features shows that quite quickly. You essentially only get the automatic low-latency mode ALLM and a simple Game Bar that lets you view basic signal information and change a few settings. But that is where the list of strengths ends. The TV does not support VRR or 120 Hz (not even at lower resolutions), and on top of that it has problems with a proper implementation of the HDR HGIG format. It is suitable for occasional console gaming, and thanks to low input lag controls remain responsive, but if someone is looking for a TV primarily for games, the Bravia 2 II will simply be a rather limited choice.