TCL P7K / P79K vs Haier K85F

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%.

Let’s now move on to one of the hottest topics in the world of televisions, which is the quality of HDR performance. In the case of the Haier K85F model, we unfortunately have to make it clear: if you’re looking for equipment to watch content in a wide dynamic range, you should steer clear of this model. The main issue is its very low peak brightness, which during our tests barely reached 250 nits. To give you a better idea of what that means – this level is fine for watching standard SDR content, but it’s absolutely insufficient to show any real benefits of HDR. The image simply doesn’t have the "power" to generate bright, striking highlights. All of our measurements and tests on specialised test patterns confirmed this. As if that wasn’t enough, the television also struggles with colour reproduction. In this budget build, there are no technologies that broaden the colour gamut, such as quantum dot layers (marketed as "QLED"). As a result, the coverage of the DCI-P3 colour space, which is crucial for HDR content, 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 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.

Alright, how does the television handle colours straight out of the box, without any intervention from our side? The Haier K85F offers a whole range of picture modes, such as Dynamic or Eco, but for anyone wanting to watch films according to the creators' intentions, there's essentially only one that matters: Film mode. This is where we focused our tests, and unfortunately, its name has little to do with reality. The picture on factory settings is very far from what we could call cinematic fidelity and requires many adjustments. Let's start with the white balance, which has a clear deficiency of red colour. In practice, this means the entire image has a cool, bluish tint. Even worse is the issue of brightness management, that is, the gamma curves (for SDR) and EOTF (for HDR). Their graph resembles a true rollercoaster, which terribly impacts the viewing experience. This results in unnatural dimming of SDR content, causing details in the shadows to be lost, and in the case of HDR – an excessive brightening that further exacerbates the problem of clipping. Such a combination, which consists of too cool white combined with chaotic brightness and too much blue colour saturation, leads to enormous errors in colour reproduction. Our measurements on a specialist ColourChecker chart showed errors (Delta E) regularly reaching and exceeding values of 8-9. To put it simply: errors above the threshold of 3 are 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, 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.

No good, but can anything be done about this picture? Is professional calibration able to save the situation? The answer is both yes and no. It needs to be said clearly that there are certain things we cannot overcome. The limitations of the construction itself, namely a poor panel and its narrow colour coverage, mean that you can forget about a sensible HDR effect – we won't be pulling the wool over your eyes on that. The biggest beneficiary of our adjustments is undoubtedly the SDR mode, and it is for watching such content, after calibration, that this television starts to make sense. We managed to tame the white balance in our own way. Although the television only offers basic, 2-point adjustment (rather than precise, 20-point), it's not perfect, but we successfully eliminated that unpleasant, cold "chill" in the picture. Above all, though, we noted a huge 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 an image without artificially dimming or brightening it. The conclusion is simple: even with such a cheap television, professional setting correction can achieve a great deal and extract the maximum potential from it.

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.

Let’s move on to digital processing and image scaling, specifically how the Haier K85F handles lower resolution signals, such as from regular television. Right off the bat, we encounter an incredibly annoying and completely incomprehensible issue – the overscan is enabled by default. This means the television artificially enlarges the image, cutting off its edges on every source, even 1080p. To see the full frame, you have to dig into the screen settings each time and manually switch the format to "stretch to 16:9." It's a minor detail, but devilishly frustrating. The scaling of content to 4K resolution can be described in one word: acceptable. And that's about it. The image processor doesn't strip detail from the image, nor does it generate jagged edges or other artifacts. It simply does its job, without any bells and whistles. It’s alright, but nothing more. The most significant and noticeable shortcoming in the digital processing section is, however, the absence of a tone transition smoothing feature. This is an algorithm that could significantly reduce the annoying banding effect we mentioned earlier. Unfortunately, the manufacturer did not foresee such a solution, condemning us to watch the imperfections of the panel and low-quality material in all their glory.

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.

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

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.

Let’s move on to the features for gamers, although we must point out straight away that this is more of a proposal for the "occasional" ones. The manufacturer does boast in the specifications about having HDMI 2.1 ports, which looks impressive on paper, but in reality, it’s largely a marketing ploy. What good is a modern port when 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 takes away HDMI 2.1’s key advantage. What a shame. (That’s why in our tests we note this as HDMI 2.0 ports). Another odd issue is the TV's response to an attempt to calibrate HDR from the console. Changes to brightness settings result in very unnatural image behaviour, which could suggest incorrect implementation of the HGiG standard. To be honest, one shouldn’t worry too much about this, as we have repeatedly mentioned, we simply do not recommend using any HDR content on this screen. However, to counterbalance the negatives, the Haier K85F does have two big and unexpected advantages. The first is the presence of ALLM, or automatic game mode, which switches the TV 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 operates within a very modest range of 48-60 Hz, its mere presence is commendable. Thanks to this, the image in games can “tear” less, which realistically improves the gaming experience.