LG 55 B4 vs TCL C7K / QM7K

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.

TCL C7K is one of the brightest MiniLED televisions in its price range. Under the best testing conditions, the screen managed to achieve over 1200 nits, resulting in impressive, at times almost blindingly bright scenes. And most importantly – this is not just a theory based on measurements. In practice, the brightest parts of films can shine with true cinematic grandeur. Fans of home HDR cinema should be truly satisfied.

The impression is excellent, especially in scenes with large areas of brightness – a white sky, explosions, sun reflections, or magical sunsets can surprise with an intensity of light that is rarely seen in this price range.

However, it gets a bit worse when more challenging scenarios appear on the screen, as described when discussing contrast – that is, images full of details, with small, bright elements on a dark background. In such cases, the C7K often decides to preserve black levels at the expense of brightness. An example? Scenes from the films Sicario 2 or Life of Pi, where small light sources (like a distant lantern) can become less visible, and details in the lights are simply dimmed or blend into the background.

For many viewers, this may be an acceptable compromise – as we achieve deep black levels and a pleasing plasticity of the image. Nevertheless, it is worth being aware that the visibility of small details in bright areas is not this model's strongest suit. It is simply a technological limitation that still exists – even with over 300 zones.

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.

A new feature in TCL televisions for 2025 is the long-awaited Filmmaker mode, which until now has been found in most competing brands. This is great news, as this mode is considered to be the truest to the original vision of the creators and is often recommended by enthusiasts of good picture quality. Unfortunately, as is often the case, the mere presence of this mode does not guarantee perfection. The Filmmaker mode in the TCL C7K is not without its flaws. There can be criticism of the incorrect white balance, particularly a slight dominance of blue, which resulted in cool, somewhat greyish skin tones. But that was not the biggest issue. The main complaint was the excessive brightness exposure, which is clearly visible on the gamma and EOTF graphs. The image was simply too bright, at times even blown out, which affected not only the texture of scenes but also the overall viewing experience. Some details were simply lost, and the entire image looked as if someone had slightly overcooked the brightness slider. As always, we decided to check what could be extracted from this after calibration. And that’s where it started to get really interesting…

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.

After calibration, the TCL C7K showcased itself in a really good light, especially when it comes to SDR content. We managed to precisely tune the white balance, colour gamut, and brightness characteristics to the point that colour errors on the ColorChecker palette dropped below a value of 2. For the uninitiated – this is nearly a perfect result, which means that the image is very close to what the creators intended. Unfortunately, the situation was worse with 4K HDR content. Although we managed to gently stabilize the white balance and correct its previous errors, it was still evident that the television has certain "MiniLED traits," especially in brightness management. When we checked how the C7K handled the EOTF curve on actual film scenes, rather than just on synthetic test patterns, it turned out that the screen still tends to slightly brighten the entire image. This impacts the overall experience – blacks lose some depth, and the image becomes less contrasty than it should be. Despite these minor shortcomings in HDR content, the overall reception of materials – especially in SDR – is truly very good. After calibration, the C7K can display an image that can compete successfully with much more expensive models. Good colour tuning, natural skin tones, and pleasant brightness make movie sessions and everyday viewing of content more than satisfactory.

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.

TCL C7K is equipped with a feature that, according to the manufacturer, is meant to smooth out unwanted colour transitions – a sort of rescue for less successful tonal shifts. It is called "Gradual Smoothing" and… well, it sounds ambitious, but in practice it works very poorly. Regardless of whether we set it to a low or high level, the difference is minimal. Worst of all, the feature can cut out elements from the picture that should be there. Fortunately, film grain remains untouched, so at least it doesn’t smooth everything indiscriminately, but still – it’s better to simply turn this option off.

When it comes to scaling lower resolution content, it is somewhat better. SD and HD materials look quite decent, although at times we had the impression that the image loses sharpness and becomes too soft – as if something took away its definition. Fortunately, with very low sources (e.g. 576p), there was no overscan effect, meaning the picture was not artificially cropped – everything fit on the screen as it should.

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.

The TCL C7K handles motion fluidity really very well. The matrix used in it offers a refresh rate of 144 Hz, which in itself suggests that this television is more than just a regular "60 Hz" panel. Furthermore – if we connect the C7K to a computer and set the resolution to Full HD. But we'll write more about this in the paragraph about gamers and PC collaboration. Returning to everyday use – both sports and films look very good here. Thanks to the fast panel and well-functioning motion smoothing, the C7K is great for watching matches, but also for movie screenings. In the menu, we find two sliders – motion blur reduction and flicker reduction – which allow us to adjust the fluidity effect to our own preferences. At lower settings, we get a more cinematic effect, with slight stuttering motion. At higher settings – the picture becomes more theatrical, fluid to the point of excess. Everyone has their own preferences – anyone can set it to their liking.

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.

The TCL C7K is a television that on paper appears to be the dream equipment for gamers – and most importantly, it holds up in practice too. To start with good news: there are two full-bandwidth HDMI 2.1 ports, so we can easily connect both a console and a computer, taking advantage of all their capabilities. The panel itself supports a refresh rate of 144 Hz, which gives a significant advantage in dynamic games. There is also a complete set of gaming features: VRR (variable refresh rate), ALLM (automatic low-latency mode), and support for Dolby Vision in games. There is also the HGiG mode, which allows for HDR effects consistent with the creators' intentions. GameBar, an information bar for gamers. It works quickly, looks clear (like a Nintendo console👌), and shows what matters most: the current frame rate, VRR status, and even HDR parameters.