TCL P755 vs TCL P7K / P79K

TCL P755 provides average HDR effect quality. The maximum brightness of the television 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, which affects the overall impression of contrast. However, the television offers a wide coverage of the DCI P3 colour gamut, reaching around 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 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%.

The colour reproduction in the P755 in "Movie" mode, although it is the best factory setting, leaves much to be desired. The biggest problem is the white balance, where the graph clearly shows a spike in red and a drop in green. This leads to a shift in colours towards red, making the colours on the screen less natural and potentially looking 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 skewed towards red, affecting the realism of the image and reducing the perception of colour depth. In terms of contrast, the gamma chart analysis shows considerable fluctuations, particularly in dark areas of the image, where values drop below the optimal level of 2.4. This results in darker areas being displayed brighter than they should be. Additionally, the EOTF curve, responsible for brightness reproduction, is slightly above the reference curve. The graph shows a slight boost in brightness to around 50%, followed by only a minor decrease. This leads to excessive brightness enhancement in the mid-tones of the image and may result in loss of detail and distortion in brighter scenes.

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.

After calibration, the colour reproduction on the television improves significantly when it comes to SDR content. The colour curves are now close to the ideal value, and the gamma is more stable. Although the drop at the beginning of the graph to value 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 improvement in HDR content. The white balance has been improved, resulting in a 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 tonal quality and detail have been enhanced. Dynamic tone mapping works more effectively, improving image quality in bright areas and retaining more detail.

Although the device's picture does not achieve complete perfection, calibration brings significant improvement. After adjusting the settings, the television presents itself much better, offering a 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, 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.

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 may affect the quality of tonal gradations in higher dynamic range materials.

When it comes to image scaling, the television does not perform at its best. There are noticeable edge cuts, particularly evident on the figure of the model 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. Moreover, SD quality images are displayed with slight cropping at the top as well as the bottom.

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 television offers decent, although not perfect, results in terms of motion fluidity. For films, the television features a “Flicker Reduction” function that allows for motion fluidity adjustment on a scale from 1 to 10. With this option, we can customise the appearance of the image to a cinematic or more theatrical preference (with a slower or faster pace).

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 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 television to low latency mode, significantly improving response 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 screen tearing and providing smoother gameplay. Dolby Vision for gamers enhances picture quality, 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 reaction time.

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

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.