TCL P7K / P79K vs TCL C6KS / C69KS / Q6CS

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%.

And what about HDR? Here, the C6KS performs quite well and – as has become a recurring theme of this review – identically to the C6K model. The maximum brightness generated by this television is around 600 nits. In bright scenes, this translates to a really solid, cinematic effect, and generally, the video materials look good here. However, one must keep in mind the specifics of the dimming algorithm in this model. When very small, bright points (e.g., stars) appear against a dark background, the television can dim them quite significantly. The goal is simple: to eliminate blooming and maintain the best possible blacks. This is quite a reasonable compromise. Most viewers will definitely appreciate deep, "true black" more than additional micro-details, the display of which could cause the screen to appear greyed out. This is the nature of local dimming technology in this price range, and one must be aware of it. It is also worth noting that the TCL C69KS (C6KS) has an additional PFS coating, which is marketed under the slogan of QLED technology. Thanks to this, the colours are saturated and vibrant – our measurements showed that the coverage of a wide colour gamut reaches as much as 92% here.

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.

Unlike the more expensive C6K model, the tested C6KS does not have an option in the menu labelled as Filmmaker Mode. Is this a reason to cry? Absolutely not. Our tests have shown that in practice, in terms of colour reproduction, the lack of this specific label makes virtually no difference. The best available Film/Cinema mode here offers an almost identical picture characteristic to the aforementioned Filmmaker in the more expensive model. So we get a very similar image, just under a different name. Therefore, if you were wondering whether paying extra for the C6K gives you better colours – the answer is no, in both cases the base is the same and requires slight adjustments.

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, the C69KS's tendency to distort colours has been effectively limited, resulting in a very good final effect. After calibration, we will no longer see excessive warming of scenes in SDR or overly cool tones in HDR. However, it is worth noting the brightness characteristics. In SDR content, it is hard to have any objections – the image looks very good, especially in older films, television programmes, or materials from YouTube. It is significantly more challenging to evaluate the television's performance in HDR. Analysis of the EOTF curve suggests correct behaviour, but its practical variant reveals certain limitations. The C69KS can overly brighten the smallest elements of the frame, while at other times, it can dim the entire scene. Thus, calibration brought clear benefits in terms of colour quality, but certain limitations resulting from the local dimming operation and the way it is controlled by the C69KS cannot be overlooked, as we also saw in the C6K test.

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.

The C69KS handles upscaling quite well. The tested 576p material looks surprisingly decent – a considerable amount of detail is retained, and the algorithm adds a slight "rounding" effect to sharp edges, making the image appear more cohesive. The performance in smoothing tonal transitions is less impressive. The television practically cannot improve them, leaving the image in a rather raw state. With older material, this can be quite tiring, as the lack of additional processing highlights any imperfections.

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.

C69KS offers a simplified motion enhancement panel in films, allowing the adjustment of effect intensity with a slider. This makes it easy to match fluidity to personal preferences. The ability to use higher refresh rates is also a plus – although the panel operates natively at 4K at 60 Hz, lowering the resolution to 1440p enables 120 and 144 Hz modes, both on consoles and PC. This sounds like great news, however, in practice, the image at these settings exhibits significant motion blur. The effect is so pronounced that the overall presentation appears merely average and loses its appeal for everyday use.

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.

If we overlook the smudging and lack of native 4K at 120 Hz, the C69KS impresses with how well it performs during gaming. We get everything one can expect from a gaming television: variable refresh rate (VRR), automatic switching to game mode (ALLM), Dolby Vision Gaming mode, and a well-functioning HGiG. The television can also operate at 120 and even 144 Hz at lower resolutions, allowing for smoother gameplay on a console or PC. Additionally, there is a clear Game Bar that lets you quickly glance at key settings while gaming. As a result — despite a few limitations — the C69KS can be a really successful screen for gamers.