TCL P7K / P79K vs Haier K85F

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%.

Let’s now turn to one of the hottest topics in the world of televisions, namely the quality of HDR effect. In the case of the Haier K85F model, we must unfortunately make it clear: if you are looking for equipment to watch content in a wide dynamic range, you should avoid this model at all costs. The main problem is its very low peak brightness, which during our tests barely reached 250 nits. To give you a better idea of what that means – such a value is fine for watching standard SDR content, but it is absolutely insufficient to showcase any real benefits of HDR. The image simply lacks the "power" to generate bright, striking highlights. All our measurements and tests on specialist patterns only confirmed this. As if that weren't enough, the television also struggles with colour reproduction. In this budget build, we won't find any technologies to expand the colour palette, such as quantum dot layers (marketed as "QLED"). As a result, the coverage of the DCI-P3 colour space, which is crucial for HDR materials, is only around 80%. In practice, this means that the image will not only be dark but also devoid of the vibrant, saturated colours that the director wanted to show us.

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.

Well, how does the television perform with colours straight out of the box, without any interference from our side? The Haier K85F offers a full range of picture modes, such as Dynamic and Eco, but for anyone who wants to watch films according to the creators' intentions, only one really matters: Film mode. That is where we focused our tests, and unfortunately, its name has little to do with reality. The picture in the factory settings is very far from what we could call cinematic fidelity and requires numerous adjustments. Let's start with the white balance, which has a noticeable deficiency of red. In practice, this means that the entire image has a cool, bluish tint. The situation is even worse regarding brightness management, namely the gamma curve (for SDR) and EOTF (for HDR). Their graph resembles a real rollercoaster, which has a disastrous impact on the viewing experience. This results in unnatural dimming of SDR content, causing details in shadows to be lost, and in the case of HDR – excessive brightness, which further exacerbates the issue of clipping. Such a combination, namely too cool white combined with chaotic brightness and excessive blue saturation, results in significant errors in colour reproduction. Our measurements on the specialist ColorChecker chart revealed errors (Delta E) regularly reaching and exceeding values of 8-9. Put simply, errors above the threshold of 3 are already easily noticeable to the naked eye, so such a result means that the colours on the screen are simply heavily distorted.

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.

Well, is there anything that can be done about this picture? Can professional calibration save the situation? The answer is both yes and no. It must be clearly stated that there are certain limitations we cannot overcome. The constraints of the design itself, meaning simply a poor panel and its narrow colour coverage, make it impossible to expect a reasonable HDR effect – we won't mislead you on that. The biggest beneficiary of our adjustments is undoubtedly the SDR mode, and it is indeed for watching such content, after calibration, that this television starts to make sense. We managed to somewhat tame the white balance. Although the television only offers basic 2-point adjustment (rather than precise 20-point), so it's not perfect, we successfully eliminated that unpleasant, cold "chill" in the picture. Above all, however, we noted a significant improvement in brightness management. The gamma curve, which previously resembled a rollercoaster, looks like an almost perfectly straight line after calibration. This is a sign that the television can finally display images without artificially dimming or brightening them. The conclusion is simple: even with such a cheap television, professional adjustment of the settings can achieve a lot and extract the maximum potential from it.

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.

Let's move on to digital processing and image scaling, specifically how the Haier K85F handles lower resolution signals, such as those from standard television. Right from the start, we encounter an extremely annoying and completely incomprehensible issue – overscan that is enabled by default. This means that the television artificially enlarges the image, cropping its edges, and this happens on every source, even 1080p. To see the full frame, you have to dig through the screen settings each time and manually switch the format to "expand to 16:9". It's a detail, but it's devilishly frustrating. The very act of scaling content to 4K resolution can be summed up in one word: acceptable. And that's about it. The image processor does not strip details from the picture, nor does it generate jagged edges or other artifacts. It simply does its job, without any fireworks. It's alright, but nothing more. However, the biggest and most noticeable shortcoming in the digital processing section is the absence of a smooth tonal transition feature. This is an algorithm that could significantly reduce the annoying banding effect we mentioned earlier. Unfortunately, the manufacturer did not provide such a solution, condemning us to watch the imperfections of the panel and low-quality materials in full view.

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 matrix in the K85F model operates at a native refresh rate of 60 Hz, which right from the start sets certain expectations regarding image fluidity. However, we must admit that we were very positively surprised when we found two separate sliders for motion control in the settings menu: one labelled as "Motion Blur Reduction" and the other "De-Judder". Such generosity in this price segment is an absolute rarity, as typically manufacturers offer at most one shared option. Unfortunately, our enthusiasm waned as quickly as it appeared. It soon became clear why Haier was so "generous" – the slider responsible for motion blur reduction is simply a dummy. Its adjustment brings absolutely no visible effect on the screen, so only one of the two options works.

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.

Let's move on to features for gamers, although we must emphasise at the outset that this is more of a proposal for the "casual" ones. The manufacturer boasts in the specifications about the presence of HDMI 2.1 ports, which looks impressive on paper, but in reality, it is largely a marketing ploy. What good is a modern port if the heart of the television is a panel with a refresh rate of 60 Hz? It physically cannot display a signal at 120 frames per second, even at lower resolutions, which deprives the HDMI 2.1 port of its most significant advantage. It's a shame. (That’s why we mark it as HDMI 2.0 in our tests). Another curious peculiarity is the television's reaction to attempts to calibrate HDR from the console level. Changes to brightness settings cause very unnatural image behaviour, which might suggest an incorrect implementation of the HGiG standard. To be honest, however, one shouldn't worry too much about this, because as we've mentioned numerous times, we simply do not recommend using any HDR content on this screen. However, to avoid being too negative, the Haier K85F also has two significant and unexpected advantages. The first is the presence of ALLM, or Auto Low Latency Mode, which switches the television to low latency mode as soon as it detects a connected console. The second, even bigger surprise, is support for VRR, or Variable Refresh Rate. While it works within a very modest range of 48-60 Hz, its mere presence is commendable. As a result, the image in games can experience less "tearing," which significantly improves the gaming experience.