TCL P7K / P79K vs TCL C9K

When it comes to assessing HDR performance, we need to be clear and straightforward without any marketing fluff: the P7K/P79K is not and never was meant to be a champion in this area. The maximum peak brightness that this panel can generate hovers around just 300 nits. This represents a threshold, a sort of thin red line between what can be considered barely satisfactory HDR signal and what is, in reality, only slightly better than standard dynamic range (SDR), unfortunately leaning towards the latter. Synthetic tests confirmed this harsh reality – our measurements taken during movie sessions showed that the luminance in key bright scenes rarely exceeded 200-250 nits. Therefore, this is not a TV that would allow content created in a wide tonal range to truly shine, and that must be openly acknowledged.

Unfortunately, the issue of colour reproduction is presented just as conservatively. Although the manufacturer positions this model within the "QLED" family, owing 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%. Compared to the market, this is at best an average result, since most devices that utilise additional layers to expand the colour spectrum easily achieve values at a minimum of 90-92%.

As we mentioned regarding black levels and contrast – the C9K can make a huge impression in synthetic tests. Our measurements showed that on a screen 10% filled with white, the television can achieve... 4000 nits of brightness! It sounds out of this world, but – and here's where the pattern unfortunately repeats – the numbers say one thing, and the practical experience says another. In real movie scenes, the situation looks different. In the best-case scenario, when light effects occupy a large part of the image and the local dimming algorithm doesn't have to ponder too much about what to do with thousands of zones, the effect is really quite good. At that point, the C9K can hit around 1500 nits, which delivers a pleasant, intense burst and can indeed leave a positive impression.

The problem arises with smaller elements – such as stars in the sky, the moon, or individual reflections. That's when the proverbial cat comes out of the bag: the algorithms are not yet refined, and brightness drops to as low as 400–500 nits. That's a huge difference from the potential 4000 nits we saw in lab tests. Why does this happen? Most likely, the television is trying to protect the black levels in this way and minimize the halo effect around bright objects. Unfortunately, this comes at the expense of detail – some details simply vanish, and the scene loses its nature.

Every reliable assessment of image quality must start with selecting the most optimal, factory preset mode. In the case of the tested P7K/P79K model, the choice was made without hesitation for the "Film" mode. It is the mode that presents an image closest to the intentions of its 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 is not without a few stumbles. The most noticeable shortcoming turned out to be the not entirely correctly set white balance. A slight dominance of the blue component gives the image a subtly cool, frosty character, straying from the ideal neutrality that the director intended to show us. The television handles the reproduction of greyscale in the standard dynamic range much better – the gamma curve is almost exemplary. The only slight reservation can be made for the darkest parts of the image, where a delicate deviation from the norm causes a loss of some detail in the shadows. The most significant challenge, however, for the TCL software was interpreting the HDR signal, as illustrated by the EOTF curve. The television follows its own, rather free path here – the darkest details are disproportionately brightened, followed by a noticeable slowdown in brightness increase for mid-tones. Fortunately, most of these imperfections are of a software nature, which can be eliminated. With that thought in mind, we proceeded to the process of professional calibration.

For colour tests, we once again reached for the Filmmaker mode – a new feature in TCL televisions for 2025. While the direction is a step in the right way, the execution leaves a lot to be desired. The white balance in SDR content turned out to be too warm – there was an excess of red. On the other hand, in HDR, it swung in the opposite direction: the image became excessively blue. The Colour Checker test revealed quite a few colour inaccuracies that were noticeable to the naked eye. An even bigger problem turned out to be what we mentioned above – brightness management. Regardless of whether we were watching SDR or HDR content, the image tended to wash out the entire scene, giving it an unnatural, almost grotesque character. Therefore, it’s hard to call this a "director's mode" – because no director has ever seen such an image.

The calibration process turned out to be spot on, especially in the context of standard dynamic range (SDR) content. We successfully managed to eliminate the tendency of the television to showcase cool tones, restoring white to its natural neutrality. Moreover, the precise adjustment allowed us to correct a slight error in the gamma curve, enabling the darkest parts of the image to regain proper depth, without any signs of unnatural brightness. The results are measurable and impressive – in the ColorChecker test, the vast majority of colour reproduction errors fell below the perceptual threshold, achieving a deltaE value of below 2. This is a result that more expensive models would not be ashamed of. Unfortunately, in the case of HDR content, we encounter a wall in the form of the panel's structural limitations. And although we managed to bring the colours into line, the software's specifics mean that the television still adapts brightness in its own way, as evidenced by the persistent, non-standard EOTF curve. To summarise, calibration adds tremendous value, but it is important to be aware that it won't overcome certain physical barriers. The slightly elevated blacks, resulting from the lack of local dimming, and limited peak brightness mean that HDR content won't always be able to showcase its full potential. This is simply not the main task of this display; its true strength, especially after professional tuning, lies in viewing SDR material.

After calibration, we finally managed to tame the white balance – and it immediately translated into a more natural image. Colours finally started to look as they should, and the overall presentation was incomparably better than on the factory settings. In other words – it’s worth taking a moment to improve this, as the gain is really significant. The gamma responsible for brightness management also managed to be brought into order in SDR content, and the effect was more than satisfactory. Unfortunately, when we turned on HDR materials, the situation quickly became complicated. No matter how we set the local dimming, the television had a tendency to do what it liked with the image – either it overexposed everything or darkened the darkest parts too much. Just like we saw in the scene from the movie Billy Lynn. Colour-wise, the improvement after calibration makes a great impression, but brightness management in HDR remains the Achilles' heel of the C9K and presents a certain technological limitation.

After a series of harsh evaluations, thankfully, it’s time for some praise, and this is deserved by 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 models; nonetheless, in the price segment represented by the P7K/P79K, the results achieved are more than solid. The function that smooths tonal transitions performs particularly well, effectively eliminating posterization, which are the characteristic bands often visible in materials with higher compression, for instance, from choose.tv. The algorithm can elegantly remove unwanted gradients, which ultimately looks really good. The television also handles upscaling competently, which means the task of raising low-resolution materials to 4K standard. The resulting image, although it may seem a bit too sharp out of the box, is fortunately not a problem. The software allows for free adjustment of this parameter using a sharpness slider, allowing the final appearance to be easily tailored to personal preferences.

Digital image processing on the TCL C9K is rather average. The smooth tone transition feature seems to be present, but activating it practically changes nothing – colour bands are still visible, and it can unintentionally highlight elements we’d rather keep hidden, such as object textures. Fortunately, it doesn’t remove film grain, but that’s poor consolation given that the effects are still meagre. It’s therefore hard to recommend using this option.

On the other hand, image scaling presents itself much better. Lower quality materials look quite decent – characters and backgrounds are rendered clearly, although of course, with sources like 576p, the laws of physics cannot be fooled. Occasionally, there’s characteristic edge distortion of objects, but that’s the fault of the source itself, not the algorithm. A plus for not having issues with overscan – the image isn't artificially cropped or enlarged.

The issue of fluidity and sharpness of motion image is inextricably linked to the fundamental parameter of the panel, and in the case of the TCL P7K/P79K, we are dealing with a panel that has a native refresh rate of 60 Hz. This specification at the outset defines its capabilities and makes it hard to unequivocally recommend it to enthusiasts of dynamic sports broadcasts. During quick camera movements, the image loses sharpness, and the panel also shows a slight tendency to smudge, 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 materials recorded at 24 or 30 frames per second. Thanks to a dedicated slider, the user can decide on the final nature of the motion – from maintaining a fully cinematic, slightly jerky image, to achieving a very smooth, almost theatrical effect. It is a simple yet effective tool that allows one to adjust the viewing experience to their own preferences.

Similar to the C8K, the C9K is also a really fast TV – both figuratively and literally. It features a 4K panel with a refresh rate of 144 Hz, and at lower resolutions, the panel can even ramp up to 288 Hz. Such speed translates into practice – while watching sports or playing games, the image looks very smooth and clear. Additionally, in movies, we get an extra motion smoother called Motion Clarity, which allows you to adjust the smoothness to your own preferences – from cinematic "judder" to almost theatrical smoothness.

Although on paper the native 4K@60Hz matrix might suggest that the TCL P7K/P79K is not a TV tailored for gamers, the reality turns out to be surprisingly different. On the contrary, the manufacturer has ensured a rich set 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 rounded off with 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 TV effortlessly supports a high refresh rate signal of 120Hz, but at lower resolutions – 1080p and 1440p. This is fantastic news for console owners, who know how rarely games run in native 4K at a full 120 frames per second. The option to choose between higher resolution and doubled smoothness is therefore an incredibly sensible compromise.

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

From a gaming perspective, the TCL C9K is a complete tool. It features two (out of four) full bandwidth 48 Gbps HDMI 2.1 ports, so all the key technologies work: VRR (Variable Refresh Rate) and ALLM (Auto Low Latency Mode). Additionally, the manufacturer has included a really intuitive Game Bar that allows you to quickly check the most important parameters and adjust settings without fumbling through menus. Also, TCL's policy is a plus – the TV isn’t afraid of any HDR formats, even in game mode. Whether it's HGiG or Dolby Vision for the Xbox Series S/X console – everything works as it should, giving the player plenty of freedom.