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

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.

Sony Bravia 2 II isn't a particularly bright TV and unfortunately that's immediately obvious in HDR. In our measurements brightness stayed around 300 to 330 nits, which is far too low for the brightest parts of the image to look truly impactful. In practice HDR here doesn't differ that much from regular SDR. Bright highlights, the sun or lamps are of course visible, but they lack the intensity you'd expect from HDR content. The Bravia 2 II is therefore much better suited to standard SDR material, where its limited brightness will be least noticeable.

Colour gamut coverage

The Sony Bravia 2 II also doesn't impress when it comes to colour. The TV doesn't use any extra gamut-expanding filter, such as the quantum dots found in QLED sets or a PFS phosphor layer. In our measurements it covered about 78% of the DCI-P3 gamut and roughly 57% of the very wide BT.2020. That's definitely too little to deliver 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 is much better matched to the standard Rec.709 gamut used for films, series and SDR broadcast.

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.

The out-of-the-box colour reproduction in Kino mode was really quite good, at least for ordinary SDR material. The Bravia 2 II had a slight tendency to boost reds, which made some colours lean a bit warmer, at times with a faint pinkish tint. That wasn't a major fault and during normal viewing the picture still looked fairly natural. There was a bit more going on with image brightness. Looking at the gamma curve, 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 large part of the image becomes darker than it should. However, the difference isn't big enough to seriously bother during everyday watching. Overall, SDR straight out of the box performs quite decently.

The situation is much worse in HDR. We've already mentioned the limited colour gamut, but on top of that the Bravia 2 II quite aggressively manipulates image brightness. The EOTF curve sits below the reference for much of the range, which means the TV renders most mid and brighter parts of the 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 gives HDR that not only lacks much punch but can simply look too dark.

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.

Calibration did a lot for the Bravia 2 II, especially with SDR content. Above all, we managed to even out the white balance and tidy up the gamma, which now stays much closer to the reference value. As a result, the image no longer has the earlier pink cast, and the brightness across different areas is much better organised. You can also see it in the colour errors, which after calibration dropped to a very low level (with only minor issues in the most saturated reds).

We also partly managed to rein in the Bravia 2 II in HDR, especially in the way the TV handles image brightness. However, there is one thing no calibration can fix: the panel's capabilities. A narrow colour gamut means the TV physically can't reproduce the most saturated colours recorded in HDR content. On top of that, the low contrast of the IPS panel causes darker scenes to be covered in a grey haze, which robs colours of some of their depth. So we can improve how the Bravia 2 II uses its capabilities, but we can't 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 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.

Upscaling on the Bravia 2 II performs quite well and the TV maintains the standard we've come to expect from Sony. Lower-resolution material is sensibly upscaled to 4K, and the image is slightly smoothed without excessive edge sharpening. It's less successful at dealing with content that shows visible compression artefacts. That's down to the "Digital Noise Reduction" function, which on the "High" setting can smooth some ugly banding. The problem is it does so quite aggressively and, along with the imperfections, removes a lot of fine detail, including natural film grain. What's more, when there's more motion on screen its effectiveness drops considerably and the improvement is minimal. For that reason we generally didn't use this feature for everyday viewing.

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.

Bravia 2 II uses a 60 Hz panel and, for what it is, handles motion quite well. However, bear in mind it’s an entry-level panel and its limitations are especially noticeable with sports. The TV can’t interpolate 50/60 fps material to a higher refresh rate, so it can’t further improve the sharpness of fast-moving objects. For films and series there’s a conventional motion-smoothing feature that can reduce the judder typical of 24 fps material.

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.

The Bravia 2 II isn’t a TV that’s particularly suited to gaming, and the feature list makes that clear pretty quickly. You basically only get automatic low-latency ALLM and a simple Game Bar where you can view basic signal info and change a few settings. That’s where the positives end. The TV doesn’t support VRR or 120 Hz (not even at lower resolutions) and on top of that it has problems correctly implementing HDR HGIG. It’s fine for occasional console play and, thanks to low input lag, the controls remain responsive, but if you’re after a TV primarily for gaming the Bravia 2 II is a significantly limited choice.