TCL P7K / P79K vs TCL C6K

When turning to the assessment of HDR performance, we must be clear and without marketing embellishments: the P7K/P79K is not, and was never intended to be, a master in this field. The maximum peak brightness that this panel can generate hovers around a mere 300 nits. This represents a threshold, a kind of thin red line between what can be considered a barely satisfactory HDR signal and what is, in fact, not much different from standard dynamic range (SDR), unfortunately leaning towards the latter. Synthetic tests found brutal confirmation in reality – our measurements taken during movie screenings showed that luminance in key bright portions of the scenes rarely exceeded the ceiling of 200-250 nits. Thus, this is not a television that would allow content realised in a wide tonal range to spread its wings, and this must be openly admitted.

Unfortunately, the issue of colour reproduction is presented with equal restraint. Although the manufacturer positions this model within the "QLED" family, thanks to the use of a PFS LED filter, the results do not match the heightened expectations. The coverage of the wide DCI-P3 colour gamut reaches only 86%. In the context of the market, this is at best an average result, as most devices that employ additional layers to expand the colour spectrum easily achieve values at a minimum level of 90-92%.

TCL C6K is a moderately bright television that can showcase its full potential under the best cinematic conditions – the maximum brightness is around 600 nits. In scenes with large, intense light sources, the HDR effect can be truly satisfying, providing a sense of cinematic sparkle. However, it is important to remember that when managing backlight zones, there are occasions where some elements are dimmed, and at times become barely visible. It is clear that there is a lack of proper algorithm optimisation here, although looking at the technical parameters in this price range, the overall construction performs exceedingly well.

Every accurate assessment of image quality must begin with selection of the most optimal factory mode. In the case of the tested model P7K/P79K, the choice was made without hesitation for the "Film" mode. It is this mode that presents an image closest to the intentions of the creators, avoiding both the exaggerated brightness of the dynamic mode and the excessive dimming known from eco settings. And it must be admitted that, for a device in this price range, the factory calibration is surprisingly decent, although it has not escaped a few missteps. The most noticeable flaw turned out to be the not completely correctly set white balance. A slight dominance of the blue component gives the image a subtly cool, cold character, thus deviating from the exemplary neutrality that the director wanted to show us. The television performs much better in reproducing the greyscale in the standard dynamic range – the gamma curve is nearly exemplary. The only minor reservation could be made regarding the darkest parts of the image, where a slight deviation from the norm causes a loss of some detail in the shadows. The most serious challenge for the TCL software, however, was interpreting the HDR signal, as illustrated by the course of the EOTF curve. The television follows its own, quite free path here – the darkest details are disproportionately brightened, after which there is a noticeable slowdown in the increase of brightness for midtones. Fortunately, most of these imperfections are software-related issues that can be eliminated. With this thought in mind, we began the process of professional calibration.

In this year's TCL televisions, the Filmmaker mode has appeared, and it must be admitted that it is definitely the best choice straight out of the box. This is the mode we recommend for daily watching of films and series. Unfortunately, as is often the case, the best does not mean perfect. In the case of SDR content, the image was too warm, as the red was quite pronounced in the white balance. Conversely, with HDR content, we had the opposite impression – the image became cooler than it should have been due to an excess of blue. Additionally, the brightness characteristics sometimes led to overexposure. In practice, this resulted in quite noticeable errors in colour tests, which are difficult to accept in a mode advertised as "from the creators."

The calibration process turned out to be spot on, particularly in the context of standard dynamic range (SDR) content. We successfully mitigated the television's tendency to emphasize cool tones, restoring the whiteness to its natural neutrality. Moreover, precise adjustments allowed us to correct a slight error in the gamma curve, ensuring that the darkest parts of the image regained their proper depth, without any trace of unnatural brightness. The effects are measurable and impressive – in the ColorChecker test, the overwhelming majority of colour reproduction errors fell below the perceptual threshold, achieving a deltaE value of under 2. This is a result that pricier models would not be ashamed of. Unfortunately, when it comes to HDR content, we encounter a barrier in the form of the inherent limitations of the panel itself. And although we managed to bring the colours into line, the software's characteristics mean that the television still adapts brightness in its own way, as evidenced by the persistent, non-standard EOTF curve. In summary, calibration adds immense value, but one must be aware that it cannot overcome certain physical barriers. The slightly elevated black level, due to the lack of local dimming, along with limited peak brightness, means that HDR content may not always be able to showcase its full potential. This is simply not the primary task of this display; its true strength, especially after professional tuning, lies in the viewing of SDR material.

Thanks to the white balance adjustment, it was possible to significantly reduce the C6K's tendency to distort colours, which translated into a very good final result. After calibration, we will no longer observe the effect of excessive warmth in SDR scenes or overly cooling the image in HDR. However, it is worth taking a closer look at the brightness characteristics. In SDR content, it is difficult to have major objections – the image looks really good, especially in older films, television programmes, or materials from YouTube. It fares much worse in the case of HDR content. An analysis of the EOTF curve suggests that everything is fine, but in practice (EOTF in films), the limitations of the design become apparent. The television tends to over-brighten the smallest parts of the frame, and in other situations, it can dim an entire scene too much. The effect of calibration is therefore evident, and in terms of colour, the C6K has gained quite a lot, but certain limitations arising from local dimming and, in fact, from its management by the C6K simply cannot be overcome.

After a series of harsh evaluations, fortunately, the time comes for praise, and this is due to the TCL AiPQ image processor for its work in the field of digital processing and content scaling. It should be noted right away that we are not talking about the level known from flagship designs; however, in the price segment represented by the P7K/P79K, the results achieved are more than solid. The feature for smoothing tonal transitions performs particularly well, effectively eliminating posterisation, which are the characteristic bands often visible in highly compressed materials, for example, from the ChooseTV service. The algorithm adeptly removes unwanted gradients, which ultimately looks really good. The television also handles upscaling competently, which is the task of elevating low-resolution materials to 4K standard. The resulting image, although it may initially seem a bit too sharp, fortunately, is not a problem. The software allows for free adjustment of this parameter using a sharpness slider, making it easy to customise the final appearance to personal preferences.

TCL C6K performs quite well in terms of scaling. Lower quality materials look acceptable, and the absence of overscan issues means that the image is displayed in full, without cropping. However, one cannot expect miracles – very low-quality content will not gain a new life here, as the image processor has its limitations. On thin lines or details, there is a noticeable characteristic jerking, which reveals the lack of advanced image enhancement algorithms. It is also a pity that the C6K lacks the feature for smoothing tonal transitions – in older films or video materials, colour banding can be noticeable and can be distracting during longer viewing sessions.

The issue of fluidity and sharpness of the image in motion is inextricably linked to a fundamental parameter of the matrix, and in the case of the TCL P7K/P79K, we are dealing with a panel with a native refresh rate of 60 Hz. This specification defines its capabilities from the outset and makes it difficult to unequivocally recommend it to enthusiasts of dynamic sports broadcasts. During fast camera movements, the image loses sharpness, and the panel also shows a slight tendency to smearing, which may be noticeable to more sensitive viewers. Fortunately, not everything in this aspect has been left to chance. The manufacturer has implemented a simple motion smoothing system, which is primarily used in film material recorded at 24 or 30 frames per second. Thanks to a dedicated slider, users can decide for themselves the final character of the motion – from maintaining a fully cinematic, slightly juddery image to achieving a very smooth, almost theatrical effect. It is a simple but effective tool that allows users to tailor the viewing experience to their own preferences.

The TCL C6K utilises a 144 Hz panel, which is a significant advantage in this price range. This is an important step forward compared to the previous model, the C655 PRO, which only offered 60 Hz in 4K. The difference is especially noticeable when watching sports or gaming – the ball, players, or fast action in a game are shown more clearly and without losing details. Interestingly, the panel can also operate at 240 Hz, which the manufacturer does not mention in the official materials. We will return to this topic when discussing the PC gaming mode.

TCL has also added a feature for those watching films: "Motion Clarity", which allows users to adjust the image to their liking using two simple sliders. One can either keep the film frame visible or opt for a very smooth, almost theatrical effect. This way, everyone can find settings tailored to their taste.

Although on paper the native 4K@60Hz panel might suggest that the TCL P7K/P79K is not a television tailored for gamers, the reality is surprisingly different. On the contrary, the manufacturer has ensured a rich package of features that make it a very friendly companion for next-generation consoles. Onboard, we find key technologies such as ALLM, which provides automatic switching to low latency mode, and VRR, or variable refresh rate, which eliminates screen tearing. The list is complemented by support for Dolby Vision Gaming and a simple yet functional Game Bar. However, the real and extremely pleasant surprise is something else. It turns out that the television easily supports a high refresh rate signal of 120 Hz but at lower resolutions – 1080p and 1440p. This is fantastic news for console owners, who know well how rarely games run in native 4K at a full 120 frames per second. The ability to choose between higher resolution and doubled smoothness is therefore an extremely sensible compromise.

In summary, although the P7K/P79K may not be the target screen for the most passionate tournament players, for the casual or occasional console user, it offers a package of options that is hard to find among many competitors at this price.

The TCL C6K is a television that can confidently be described as equipment designed with gamers in mind. Here we have 4K at 144 Hz, VRR support, automatic game mode (ALLM), and Dolby Vision Gaming. Additionally, there is a practical Game Bar, which is a panel with the most important settings easily accessible – useful when we want to quickly change something during gameplay (e.g. screen aspect ratio: Yes, it can be done!). The wide range of VRR is also noteworthy, reaching up to 240 Hz. However, this option is primarily for PC gamers who will drop the resolution below native 4K. At that point, the television can spread its wings and demonstrate extra fluidity, especially in fast-paced esports titles. In the case of consoles, we stick to the classic limit of 120 Hz, but the possibilities are still really broad. The only drawback might be slight ghosting, which can sometimes be seen in dynamic scenes. Apart from that, though, the C6K offers everything that gamers expect from a television.