TCL P7K / P79K vs TCL C9K

When evaluating the HDR effect, we must make it clear and without marketing embellishment: the P7K/P79K is not and was never meant to be a master in this field. The maximum peak brightness that this panel can generate is only around 300 nits. This is a borderline value, a sort of thin red line between what can be considered a barely satisfactory HDR signal and what is really 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 parts of the content rarely exceeded the threshold of 200-250 nits. Therefore, this is not a television that would allow content produced in a wide tonal range to truly shine, and we must openly acknowledge that.

Unfortunately, the issue of color reproduction is presented equally restrained. Although the manufacturer positions this model in 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 color gamut is only 86%. Compared to the market, this is at best an average result, as most devices that employ additional layers to expand the color spectrum easily achieve values at a minimum level of 90-92%.

As we mentioned with black 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 is capable of squeezing out… 4000 nits of brightness! It sounds astronomical, but – and here, unfortunately, the pattern repeats – the numbers say one thing, and practice says another. In real movie scenes, the situation looks different. At best, when the light effects occupy a large part of the image and the local dimming algorithm does not have to think too hard about what to do with thousands of zones – the effect is really good. At that point, the C9K can reach around 1500 nits, which provides a pleasant, intense flash and can indeed make a positive impression.

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

Every reliable image quality assessment must begin by selecting the most optimal factory mode. In the case of the tested model P7K/P79K, the choice was confidently made for the "Film" mode. It is this mode that presents an image closest to the creators' intentions, avoiding both the exaggerated brightness of 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 free from a few stumbles. The most noticeable flaw turned out to be an imperfectly adjusted white balance. A slight dominance of the blue component gives the image a subtly cool, chilly character, thus deviating from the exemplary neutrality that the director wanted to show us. The television performs much better in reproducing the grayscale in a standard dynamic range – the gamma curve is executed almost perfectly. A minor reservation can only be made for 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 TCL's software, however, was the interpretation of the HDR signal, which is 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 midtones. Fortunately, most of these imperfections are software-related issues that can be eliminated. With this thought in mind, we proceeded to the professional calibration process.

For color tests, as always, we reached for the Filmmaker mode – a new feature in TCL TVs for 2025. And while the direction itself is a step in the right direction, the execution leaves much 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 went in the opposite direction: the image became excessively blue. The Colour Checker test revealed quite a few color errors 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 blow out the entire scene, giving it an unnatural, even grotesque character. It's hard to call this a "director-created" mode – because the director has certainly never seen such an image.

The calibration process turned out to be a home run, especially in the context of standard dynamic range (SDR) content. We successfully managed to eliminate the TV's tendency to emphasize cool tones, restoring the whites to their natural neutrality. Furthermore, precise adjustments allowed us to correct a slight error in the gamma curve, so the darkest areas of the image regained their proper depth, without a trace of unnatural brightening. The effects are measurable and impressive – in the ColorChecker test, the vast majority of color reproduction errors fell below the perceptual threshold, achieving a deltaE value below 2. This is a result that would not shame much more expensive constructions. Unfortunately, in the case of HDR content, we hit a wall in the form of the inherent limitations of the panel itself. And although we managed to bring the colors in line, the software's specifics mean that the TV still adapts brightness in its own way, as evidenced by the persistent, non-standard EOTF curve. In summary, calibration brings tremendous added value, but one must be aware that it cannot overcome certain physical barriers. A slight boost in black levels, resulting from the lack of local dimming, and limited peak brightness mean that HDR content will not 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 the viewing of SDR materials.

After calibration, we finally managed to tame the white balance – and it immediately translated into a more natural image. Colors finally started to look the way they should, and the overall presentation was incomparably better than in the factory settings. In other words – it’s worth taking a moment to improve this, as the gain is truly significant. The gamma responsible for managing brightness was also brought into order in SDR content, and the effect was more than satisfying. 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 dimmed the darkest parts too much. Exactly as we saw in the scene from the movie Billy Lynn. So, the color improvement after calibration makes a great impression, but brightness management in HDR remains the Achilles' heel of C9K and presents a certain technological limitation.

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 digital processing and content scaling. It should be noted right away that we are not talking about the level known from flagship designs; nevertheless, in the price segment represented by the P7K/P79K, the results achieved are more than solid. The feature that smooths tonal transitions performs particularly well, effectively eliminating posterization, which are the characteristic bands often visible in materials with higher compression, such as from the YouTube service. The algorithm can elegantly remove unwanted gradients, which ultimately looks really good. The television also competently handles upscaling, which is the task of raising low-resolution materials to 4K standard. The output image, although it may seem a bit too sharp out of the box, fortunately, is not a problem. The software allows for easy adjustment of this parameter using a sharpness slider, so the final appearance can be easily tailored to personal preferences.

Digital image processing in TCL C9K is quite mediocre. The tonal smoothing feature seems to be present, but turning it on practically changes nothing – color bands are still visible, and it can unintentionally highlight elements we would prefer to hide, such as textures of objects. Fortunately, it doesn’t remove film grain, but that’s small comfort since the effects are still poor. Therefore, it's hard to recommend using this option.

On the other hand, image scaling performs much better. Lower quality materials look quite decent – characters and backgrounds are presented clearly, although, of course, with sources at 576p, physics cannot be fooled. Sometimes, characteristic aliasing on objects appears, but that’s the fault of the source itself, not the algorithm. A plus for not having issues with overscan – the image is not artificially cropped or enlarged.

The issue of fluidity and sharpness of the image in motion 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 already defines its capabilities and makes it difficult to unequivocally recommend it to enthusiasts of dynamic sports broadcasts. During rapid camera movements, the image loses sharpness, and the panel itself also shows a slight tendency to blur, 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 independently decide on the final character of the motion – from a fully cinematic, slightly juddery image to achieving a very smooth, almost theatrical effect. It is a simple yet effective tool that allows users to tailor the viewing experience to their own preferences.

Like the C8K, the C9K is also a really fast television – both figuratively and literally. It features a 4K panel with a refresh rate of 144 Hz, and at lower resolutions, the display can even ramp up to 288 Hz. This speed translates into practice – when watching sports or playing games, the image looks very smooth and clear. Additionally, in films, we get an extra motion smoother called Motion Clarity, which allows us to adjust the fluidity to our own preferences – from the cinematic "judder" frame 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 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 completed 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 TV easily supports high refresh rate signals of 120 Hz, but at lower resolutions – 1080p and 1440p. This is fantastic news for console owners who know full 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 avid tournament gamers, it offers a package of options for the casual or occasional console user that is hard to find among many competitors at this price point.

For gaming, the TCL C9K is a complete tool. Here we have two (out of four) HDMI 2.1 ports with full bandwidth of 48 Gbps, so all key technologies work: VRR (variable refresh rate) and ALLM (automatic low latency mode). Additionally, the manufacturer added a really intuitive Game Bar, which allows you to quickly preview the most important parameters and adjust settings without digging through the menu. Also, TCL's policy is a plus – the TV is not 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 wide freedom.