TCL P755 vs TCL P7K / P79K

TCL P755 provides average HDR effect quality. The maximum brightness of the TV is slightly below 300 nits. Such brightness limits the intensity of bright areas in HDR content. In practice, this means that bright elements may not be sufficiently pronounced, affecting the overall impression of contrast. However, the TV offers wide coverage of the DCI P3 colour gamut, reaching about 93%. As a result, colours are vibrant and saturated, significantly improving colour reproduction quality in HDR content. Despite the limited brightness, the wide colour range allows for richer and more realistic shades.

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%.

The colour reproduction in the P755 in "Cinema" mode, although it is the best factory setting, leaves much to be desired. The biggest issue is the white balance, where the chart clearly shows a spike in the red colour and a drop in the green colour. This leads to a shift in colours towards red, causing the colours on the screen to appear less natural and may look incorrect, especially in scenes with a white or neutral background. This is confirmed by the "Colour Checker" test, which reveals that the colours are indeed shifted towards red, affecting the realism of the image and reducing the perception of colour depth. In terms of contrast, the gamma chart analysis shows significant fluctuations, particularly in the dark areas of the image, where values drop below the optimal level of 2.4. As a result, darker areas may be displayed brighter than they should be. Additionally, the EOTF curve, responsible for brightness reproduction, sits slightly above the reference curve. The graph shows a slight increase in brightness to about 50%, after which there is only a minor drop. This leads to excessive brightness enhancement in the mid-range of the image and may result in loss of detail and distortion in brighter scenes.

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.

After calibration, the colour reproduction on the television significantly improves when it comes to SDR content. The colour curves are now close to the ideal value, and the gamma is more stable. Although the dip at the beginning of the graph to the values is still present, the overall accuracy of colour reproduction is much better. The “Colour Checker” test shows that most colour samples have errors below level 2, indicating improved colour fidelity. A few deviations are present, but generally, the colours are now more realistic and consistent with reality.

Calibration also brings improvements in HDR content. The white balance has been corrected, translating to more natural colour reproduction. The EOTF curve, although now closer to the reference curve, still shows a slight boost in brightness at the beginning of the graph. This leads to minor distortions in very bright scenes, but the overall tonality and detail have been enhanced. Dynamic tone mapping works more effectively, improving image quality in bright areas and preserving more details.

Although the image from the device does not achieve full perfection, calibration brings significant improvement. After adjusting the settings, the television performs much better, offering more realistic and accurate colour reproduction in SDR and HDR content. While some shortcomings can still be noticed, calibration effectively eliminates many previous issues, ensuring better image quality and more natural colours.

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.

The “Gradual Smoothing” function works quite well, effectively eliminating visible boundaries between different shades of the same colour. Thanks to it, tonal transitions are smoother. Unfortunately, this function is not available in HDR mode, which can affect the quality of tonal gradation in higher dynamic range materials.

In the case of image scaling, the television does not perform its best. There are noticeable edge cut-offs, particularly evident on the model's figure and the branches of trees. The blurring of details in these areas affects the overall sharpness of the image. This may be noticeable when watching content in a lower resolution. Additionally, SD quality image is displayed with slight cropping at the top as well as the bottom.

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.

The television offers decent, though not perfect, results in terms of motion smoothness. In the case of movies, the television has a "Flicker Reduction" feature that allows for adjustment of motion smoothness on a scale from 1 to 10. With this option, we can tailor the image appearance to cinema or more theatrical preferences (with lower or higher speed).

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 device offers a range of features useful for gamers, such as ALLM (Auto Low Latency Mode), VRR (Variable Refresh Rate), Dolby Vision for gamers, and Game Bar. ALLM automatically switches the TV to low latency mode, significantly improving responsiveness to commands from the controller and minimising input lag. VRR synchronises the screen refresh rate with the number of frames generated by the console, eliminating the tearing effect and providing smoother gameplay. Dolby Vision for gamers enhances picture quality by offering better colour and contrast reproduction in games that support this format. The Game Bar feature allows quick access to game settings and monitoring of key parameters such as response time.

However, the TV has some limitations. The 60 Hz panel prevents the display of signals with higher refresh rates at different resolutions, which may affect the fluidity of the image in dynamic games. Additionally, the lack of support for G-Sync technology for PC may impact the quality of gameplay on a computer. It is also worth noting that the HGiG mode, which aims to improve image quality in HDR games, does not work correctly on this model, negatively affecting the visual experience in HDR-supported games.

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.