LG 55 B4 vs TCL C7K / QM7K 55"-85"

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.

In terms of brightness, the models ranging from 55 to 85 inches in the C7K series are truly impressive. Under the best testing conditions, the 65-inch screen reached over 1200 nits, which in practice means that the brightest scenes can shine with almost cinematic brilliance. These are not just dry numbers from measurements – during viewings, the white skies, explosions or reflections of light on water looked extraordinarily striking, often giving the impression that the television exceeded its price class. This is particularly effective in scenes with large areas of brightness, where the screen is filled with intense light – such as in sunlit shots or during dynamic action sequences. Viewers seeking strong HDR will definitely be satisfied.

However, scenes that require precise control of the backlighting – with small points of light on a dark background – prove to be more challenging. Here, the C7K, despite having over a thousand zones, still dims the brightness to maintain deep blacks. The effect is that in films like Sicario 2 or Life of Pi, some details, like a distant lantern or single reflections, can be less distinct or blend into the surroundings. This is a compromise inherent in MiniLED technology – it provides excellent image depth and blacks at a level that ordinary LCDs do not offer, but this comes at the cost of limited visibility of the finest lights.

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 could be found in most competing brands. This is great news, as this mode is considered the one that most accurately represents 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 it does not guarantee perfection. The Filmmaker mode in the TCL C7K is not without its flaws. One can point out the incorrect white balance, particularly the slight dominance of blue, which resulted in cool, somewhat greyish skin tones. But that was not the biggest issue. The main complaint was excessive brightness exposure, which was clearly visible on gamma and EOTF charts. The image was simply too bright, at times even overexposed, which affected not only the texture of the scenes but also the overall viewing experience. Some details were simply lost, and the entire image looked like someone had slightly overdone the brightness slider. As always, we decided to see what could be squeezed out of it 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 presented 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 so that the colour errors on the ColorChecker palette fell below a value of 2. For the uninitiated – this is nearly a perfect result, indicating that the image closely resembles what the creators intended. Unfortunately, it looked worse with 4K HDR content. While we slightly managed to calm the white balance and correct its previous errors, it still shows that the TV has some “MiniLED traits”, particularly in brightness management. When we checked how the C7K copes with the EOTF curve on real film scenes, rather than just synthetic test patterns, it turned out that the screen still tends to slightly brighten the entire image. This affects the overall impression – the black loses 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 is capable of displaying an image that can successfully compete with much more expensive models. Good colour tuning, natural skin tones, and pleasant brightness ensure that movie sessions and everyday content viewing are 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.

The TCL C7K features a function that, according to the manufacturer, is designed to smooth out unwanted colour transitions – a sort of rescue for less successful tonal shifts. It's called "Gradual Smoothing" and... well, it sounds ambitious, but in practice, it works very poorly. Regardless of whether we set it to low or high, the difference is minimal. What's worse, the function can cut out elements from the image that should remain. Fortunately, the 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’s much better. SD and HD materials look quite decent, although at times we had the impression that the image was losing sharpness and becoming too soft – as if something was detracting from its clarity. Fortunately, with very low sources (e.g. 576p), there was no overscan effect, meaning the image 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 smoothness really very well. The matrix used in it offers a refresh rate of 144 Hz, which in itself suggests that this television is something more than a regular "60 Hz" panel. What's more – if we connect the C7K to a computer and set the resolution to Full HD. But we will write more about this in the section for gamers and cooperation with PCs. Returning to everyday use – both sports and films look very good here. Thanks to the fast panel and well-functioning motion smoother, the C7K is great for watching matches, as well as for film screenings. In the menu, we find two sliders – blur reduction and flicker reduction – which allow you to adjust the smoothness effect to your own preferences. At lower settings, we get a more cinematic effect, with a slight choppy motion. At higher settings – the image becomes more theatrical, overly smooth. Everyone 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 also holds up in practice. To start with the good news: there are two full-bandwidth HDMI 2.1 ports, so we can easily connect both a console and a computer, making full use of their capabilities. The panel itself supports a refresh rate of 144 Hz, which provides a significant advantage in fast-paced games. Additionally, it comes with a complete set of gaming features: VRR (Variable Refresh Rate), ALLM (Auto Low Latency Mode), and support for Dolby Vision in games. There is also an HGiG mode that allows for an HDR effect in line with the creators' intentions. GameBar, which is an information bar for gamers. It works quickly, looks clear (like a Nintendo console👌), and shows the most important information: the current frame rate, VRR status, and even HDR parameters.