LG 55 B4 vs LG OLED C6 (WOLED)

The brightness results in HDR materials for LG B4 are very good. It is true that none of them exceed 1000 nits, although the stability of luminance is excellent and looks practically the same in every scenario. The only moment where the tested television performs worse is the last of the scenes, although this should not be surprising. Large frames filled with a lot of white have always been, and probably will continue to be, somewhat of a weakness for OLED televisions. However, the combination of perfect contrast, black levels, and brightness of LG B4 allows for a full experience of the HDR effect. Additionally, the incredibly high coverage of the DCI-P3 colour gamut deserves recognition, reaching 99%. This makes the colours look incredibly vivid and striking.

The HDR performance of the LG C6 is really very good. LG Display's new WOLED panel has primarily brought a considerable increase in brightness. In our unit we measured around 1,500 nits and, importantly, the TV can deliver similar values in many typical film scenes. That gives the HDR the necessary impact. Bright highlights, lamps and sunlight can be really intense, and most HDR films simply look very impressive. Of course it's still an OLED, so brightness falls in scenes with a lot of white. This is well illustrated by the fifth scene in the film The Meg, where the C6 reached around 600 to 700 nits. That's still a very good result, but it also shows that the new panel hasn't shed all the limitations typical of OLEDs.

Colours

When it comes to colours, there is also little to complain about. The C6 covers about 99% of the DCI-P3 gamut and roughly 75% of BT.2020. In practice the colours are very saturated and, importantly, stable across different scenes. This is worth emphasising, because not every TV behaves the same in this respect. In some RGB Mini LED models colour saturation can depend more strongly on image brightness. A wider colour palette is nowadays offered mainly by QD-OLED TVs and new SQD models with a new generation of quantum dots. However, the C6 still performs very strongly here and is able to produce suitably saturated colours in most film scenes.

The best factory mode prepared by the manufacturer is "Filmmaker," which is exactly what we used throughout the entire testing procedure. We must admit that the unit we received out of the box had quite good colour reproduction. The biggest problem in both SDR and HDR content turned out to be white balance. In the former, a strong red hue was evident, causing the displayed image to have a pronounced yellow tint, particularly noticeable on skin tones and whites. In higher quality materials, this colour was also accentuated, but due to a lack of blue, there were also signs of green visible. Apart from these issues, we also encountered problems with grayscale and the colours themselves.

Right out of the box the LG C6 is pretty well set up, especially if you choose Filmmaker mode. In SDR material the white balance is decent, although as brightness increases it starts to lack a bit of red. The picture becomes a little cooler as a result, but it’s not such a big difference that it stands out during normal viewing. More happens in the brightness response itself. Gamma is a bit low and instead of holding at 2.4 it sits closer to 2.1–2.2 over much of the range. In practice the C6 slightly brightens midtones. Shadows are therefore more readable, but the image loses some 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 about 20–30% brightness the white balance starts to drift more and more. As brightness rises there’s more red and a noticeable lack of blue. In the brightest highlights the difference is already significant and also affects reproduction of some colors. The EOTF curve itself is handled fairly well over most of the range. The C6 only has a tendency to slightly brighten the image, which we also saw during our film comparisons. The largest deviation appears around the brightest highlights, where the TV begins to adapt the signal to the panel’s capabilities. So the out-of-the-box Filmmaker mode in HDR isn’t perfect, but overall it performs well. The biggest room for improvement is the white balance, especially at high brightness.

LG B4 has been providing very advanced calibration tools in its televisions for years. We can even say that as the only manufacturer on the market, it allows for such deep intervention in image adjustment. It is thanks to these tools that we were able to calibrate the device so well. Evidence of this is the extremely low deltaE errors, which can be said to be at a reference level. Both SDR and HDR materials now look exactly as intended by the film director. It is no coincidence that televisions of this brand are most often used as preview screens for various graphic or post-production studios.

LG TVs have been very receptive to calibration for years and the C6 is no exception. After adjustment the white balance was set almost perfectly, and most colour errors dropped to values below 3, often even around 2. In practice this means very accurate colour reproduction, both in SDR and HDR. An interesting quirk only appeared with the luminance response in HDR. On a standard EOTF chart everything looks almost ideal and at first glance it would be hard to criticise. Only when we measured the TV's behaviour with filters based on actual film scenes did it become clear that the C6 has a slight tendency to artificially boost image brightness.

This is not a huge difference and many people may even view it positively, because HDR consequently looks a little more striking. From the perspective of fidelity to the source material this is not ideal, however, as 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 very closely to the reference picture characteristic after calibration. With the C6 we are still very close to the standard, but this subtle brightness boost is indeed noticeable in films and TV series.

In this paragraph, we will take another look at the function for smoothing tonal transitions, but we will also check how the television handles lower quality material. As we have managed to verify, the setting responsible for smooth gradation works quite efficiently, although it has its weaker moments. Just as the function works correctly in SDR content, it becomes rather useless in HDR content. Even at the lowest of the options, it blurs essential details, which is why we advise against using it.

The image scaling on LG B4 is rated rather moderately positively. Although there is no edge doubling, the image itself is naturally "soft." We can change this by adjusting the sharpness slider.

Here the LG C6 has taken a real 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 in this area LG's processor this year performs excellently. The "Smooth Gradation" function in particular works very well. With heavily compressed material it can effectively hide ugly banding and artefacts that often appear, for example, in lower-quality streaming. It's best to leave it set to "Low". That way the improvement is clear and the TV does not yet start blurring fine details. Higher settings smooth the image more aggressively but can already remove some of the natural texture of objects on the screen. Upscaling itself also performs very well. Lower-resolution content is sharpened correctly, 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 maximum refresh rate that we can set on the LG B4 is 120 Hz. This is the absolute minimum for those requiring high image fluidity. The manufacturer has implemented a multi-step motion smoother called "TruMotion". It has been divided into two separate sliders adjusting the sharpness of moving images (De-Blur) and jitter (De-Judder). Both sliders can be set in the range from 0 to 10, with each degree affecting the level of fluidity, so everyone can find their golden mean.

The LG OLED B4 panel features an average response time of 0.1 ms (which directly results from our measurements), allowing for an incredibly clear image, unattainable for LCD televisions, whose response times can be as high as several milliseconds. This is clearly evident in the pictures from the "UFO Test", showing no trail following the object.

LG C6 received a panel with a maximum refresh rate of 165 Hz, which is great news above all for gamers using a powerful PC. In films, sport or on consoles we will of course make use of up to 120 Hz, but even then it is hard to fault the motion clarity. As befits an OLED, the panel's response time is almost instantaneous. Moving objects therefore do not leave the characteristic smearing or trails that we can still see on LCD televisions. This is especially noticeable in sport and fast-paced games, where the picture remains very clean even during dynamic movement.

For films and television LG has also prepared the TruMotion motion smoothing system. In the user settings you will find two separate sliders. De-Judder primarily addresses low frame-rate content, that is mainly films and TV series at 24 fps. You can use it to slightly reduce the characteristic judder or set a higher value if you want a very smooth image. De-Blur is useful for higher frame-rate material, chiefly sports broadcasts and 50/60 fps television.

The LG B4 television is equipped with four fully-fledged HDMI 2.1 ports with a full bandwidth of 48Gbps. All features that are identical to this standard were activated without any issues, and throughout the entire testing process, they did not cause any problems. The combination of such extensive functionality and low input lag suggests that the tested television is truly made for gaming. This is not surprising, considering that the manufacturer has always placed great emphasis on this. Therefore, we can enjoy both the properly implemented HGIG mode and gaming in Dolby Vision with low latency. This pairing will certainly attract the attention of all passionate gamers for whom quality is paramount.

An additional standard in televisions from this Korean manufacturer is the implementation of GameBar, allowing for quick adjustment of settings "on the fly," without the need to exit the game. It also enables image adjustments for individuals with visual impairments, which is a very nice touch. Another important piece of information is that when VRR technology is enabled, we will not experience a drop in contrast. This is thanks to the construction of the panel and the lack of conventional backlighting. However, it is normal for shades of grey to flicker slightly; nevertheless, this is a characteristic feature of this function regardless of the manufacturer or television.

In summary: the LG B4, like all of the manufacturer’s OLEDs equipped with 120Hz panels and HDMI 2.1 ports, creates a harmonious whole with the console. In practice, this is a comprehensive television, and if we expect the highest possible efficiency in gaming, B4 will be the ideal choice.

LG has long focused heavily on gamers, and the C6 really lacks nothing important. The TV supports 4K at 120 Hz from consoles, and when connected to a PC it can run at up to 165 Hz. There is also VRR from 40 to 165 Hz, ALLM and a properly working HGiG. A big plus is support for Dolby Vision in games, so the Xbox Series X can use that format without giving up Game Mode. It's rounded off by a Game Bar, from which you can quickly check key signal parameters and change settings without leaving the game. In terms of features, the C6 is therefore one of those TVs that is really hard to fault. Whether you're gaming on a PlayStation, an Xbox or a PC, practically everything you could expect from a modern gaming TV is available here.