LG OLED C5 vs Samsung QN990F

LG C5 finally does what we have been waiting for years in the C series – it exceeds 1000 nits of brightness! This is a significant change compared to previous models in the series, and it is very important – because most HDR content on streaming platforms is now created around such luminance. The image finally has the proper "shine," and the details in the highlights look as they should even without the use of dynamic metadata. However, there are scenes where the C5, like most OLED televisions, has certain issues. Especially when the screen needs to light up completely. In our test sequences, such as the bright shot from the film The Meg, the brightness clearly drops. Don't get us wrong, this result is not bad; it's more a reminder that OLED technology still has its limitations. Year by year they are becoming smaller, but still.

As for the colours? They are very good. Although the C5 does not match OLEDs with QD-OLED or Tandem RGB panels, the DCI-P3 coverage of 97% and 73% BT.2020 will satisfy even the more demanding viewers. The colours are saturated, natural, and very consistent in HDR material.

The Samsung QN990F belongs to the bright televisions category, and this is immediately evident in tests. In measurements, it achieved around 1300 nits, which in practice allows for enjoying films as their creators intended. Bright scenes have the right intensity, lights shine, and the experience is truly cinematic. In standard test patterns, sequences number 1, 3, and 5 performed best – there, brightness maintained around 800-1000 nits, and the image looked very natural. In more challenging segments, it could drop to around 600 nits, but even so, the level remained sufficient for details to be clearly visible. However, it should be added that in highly contrasting shots, the halo effect returns – the same one we mentioned regarding black levels. Bright elements can leave a halo on dark backgrounds, and this stands out immediately. Since we are dealing with a QLED, the colour palette is expanded, and the colours appear striking. The problem is that with such a flagship model, we expected better numbers. 91% DCI-P3 coverage and about 67% BT.2020 are results that can be considered solid, but not outstanding. This gives a vibrant and appealing image, yet the competition in this and lower price tiers can showcase even more.

LG C5, like other televisions we have tested, has been checked in the best possible factory mode – which remains the Filmmaker Mode. And here we have good news: in SDR materials, LG has once again done a solid job. The white balance and colour reproduction right out of the box are at a very high level. Most errors – both in balance and in the colour test (Colour Checker) – did not exceed a ΔE value of 3, which is the threshold above which differences become visible to the naked eye. Such factory settings would be desirable in a significantly larger number of televisions!

However, the situation looks different for HDR content, which is precisely what the C series was created for. Here, the C5 performs somewhat worse. The excessive presence of blue in the white balance causes the image to appear distinctly cooler – which affects, for instance, unnaturally pale skin tones or a slightly shifted tone of the entire scene. Fortunately, LG provides very precise calibration tools, and we – as always – made use of them.

We tested the QN990F in Filmmaker mode, which is the best available right out of the box. Right from the start, we noticed several significant errors. The biggest issue concerned white balance. Due to too little blue, and also improper ratios between red and blue, the image – especially in scenes with a lot of white – appeared too yellow, and at times even orange. On the Color Checker palette, these errors didn't look dramatic as they hovered around a value of 4, but in everyday viewing, especially with strong whites, they were most noticeable. We also observed issues with brightness management – the television struggled to maintain detail in the smallest parts of the image, mainly due to the way it controls the backlighting zones. Fortunately, Samsung offers a lot of room for adjustment when it comes to calibration settings. We know that with the right calibration, much more can be extracted from this screen.

We must honestly admit – in the case of the LG C5, very little was needed to achieve nearly perfect picture quality. After calibrating, we managed to reach compatibility with reference screens at a level that impresses even when compared to significantly more expensive models. The image after our adjustment looks exactly as filmmakers and series creators would want it – without colour distortions, with natural depth and subtle texture. LG has done a great job this year regarding factory settings and calibration potential. Chapeau bas!

After completing the calibration, we managed to bring the white balance back to order and eliminate the previous shortcomings in the shades of blue. As a result, the image no longer looked as if it had a slightly yellowish filter applied – the whites are purer, and the overall presentation is much more natural. We also managed, to some extent, to tame the brightness characteristics in HDR content. The television now handles detail retention in blacks significantly better and does not lose them to the same degree as before. However, when we look at the EOTF curve and the way the QN990F reproduces brightness in films, it is evident that it still tends to accentuate details in dark areas more strongly. This is a characteristic feature of Mini-LED technology and, more specifically, the way it is managed by the QN990F, which is practically impossible to completely eliminate. Despite this, after calibration, the image appears much more natural, mainly due to the correct exposure of white light. The final effect is definitely more pleasant to perceive and closer to what we expect from a flagship television.

LG C5 handles lower quality materials really very well. One of the main problems older WOLEDs faced was posterisation – that is, unwanted “stair stepping” in colour transitions. The C5 utilises a system feature that smoothens these transitions, which works surprisingly effectively. The banding effect is nearly completely eliminated, and the picture gains in coherence. Compared to last year's model, we have the impression that this feature works slightly less effectively – but the good news is that it does not undermine the structure of the image. Film grain, textures, and details remain on the screen – nothing is unnaturally smoothed out.

The C5 also excels at enhancing the quality of older recordings. Thanks to the α9 Gen6 processor (8th gen), the "scaling to 4K" performs really solidly. The image is clear, the details are sharp, and the only minor downside might be slightly noticeable edge sharpening on some borders. However, there is no issue with overscan here – the image is neither artificially cropped nor shifted, which is a significant plus and still not a given.

The biggest praise for the QN990F should be given for its upscaling. The processor responsible for "lifting" classic television to 8K resolution does quite well. While watching material in 576p signal, we had no illusions that we would suddenly see a miracle in advertising style, where the image magically transforms into crystal-clear 8K. Nevertheless, the end result was surprisingly good; the image looked clean and sharp. It’s just a shame that the television, like most Samsung models, has an overscan issue, slightly cropping the edges of the screen from the left side.

When it comes to image processing, Samsung offers a feature called "noise reduction," which in theory should improve tonal transitions in older materials, where they are usually more visible. Unfortunately, we felt quite disappointed here. The feature performs poorly – it does not handle unwanted stripes and can introduce its own artifacts. On the plus side, the television does not remove film grain when using this feature, but in practice, that is a poor consolation since the noise reduction itself proves to be virtually useless.

The LG C5 is equipped with a 144 Hz display, and this, combined with the virtually zero response time of the OLED pixels, makes it one of the best screens for watching dynamic content. It doesn't matter whether it's sports, fast-paced games, or just action – the image is razor-sharp.

And what about movies at 24 frames? LG thought of that too. The built-in "TruMotion" smoother allows you to adjust the picture to your own preferences. The "de-judder" slider increases fluidity in films, while "de-blur" gently reduces motion blur – though to be fair, it is nearly invisible here anyway.

QN990F can comfortably be called one of the fastest televisions in the world. In 4K mode, it is capable of displaying images at a frequency of up to 240 Hz, which until now has been more associated with gaming monitors than with televisions in the living room. However, in everyday viewing, what matters more is how it handles the 8K signal at 120 Hz – and here it performs very well too. Motion remains smooth, and the television manages without a hitch even with the most demanding content. Additionally, there is the motion smoother, i.e. "Picture Clarity". Thanks to it, one can adjust the image to their own preferences – leaving a slightly cinematic judder or switching to maximum fluidity, which works exceptionally well, for example, in sports broadcasts.

LG C5 is a television designed with gamers in mind – and there isn't a hint of exaggeration in that. It's hard to find anything to criticise here. We have a refresh rate of 144 Hz, full support for VRR, ALLM, and as many as four HDMI 2.1 ports with a full bandwidth of 48 Gb/s. For those who have an Xbox, PS5, Nintendo, and a gaming PC all in one room – there are no limitations, everything can be connected without any hassle.

The HDR configuration for games also poses no problems. The television correctly handles the HGiG mode, which allows for an image that matches the creators' intentions. For those interested, there is also Dolby Vision in Gaming mode, although we still recommend HGiG as the most predictable and "pure" version of HDR in games.

It also features Game Bar, which serves as a "command centre" for gamers. Everything important, from VRR settings, to picture modes, to frame rate information – is at our fingertips. The interface is simple and clear. It may look like it’s from a spaceship simulator, but it serves its purpose and just works; as it should.

C5 is truly a complete set for any gamer.

It must be said outright – the QN990F is one of those televisions that practically scream that they were designed with gamers in mind. Samsung has been developing its gaming solutions for years, but here we have a truly comprehensive set. Sure, it lacks Dolby Vision support in games, which is a downside that will always come up in discussions. However, aside from that, the list of features is impressively extensive. To begin with, we have the Game Bar – a handy menu that allows you to quickly check and change gaming-related settings. You can see, for example, the enabled VRR, frame rate, or aspect ratio settings. It’s like a little “dashboard,” making it unnecessary to dig deep into the menu to make adjustments. Speaking of VRR: yes, variable refresh rate is present here and works flawlessly. And there's ALLM, which automatically switches the television to game mode as soon as the console is powered on. These may seem like small details, but together they make using the QN990F simply comfortable and hassle-free.

However, the most impressive aspect is the number of ports. Four wireless HDMI 2.1 ports are already great news, as there is no need to choose whether to connect the console, the amplifier, or perhaps even a PC. There’s ample space for everything here. And if we add another micro HDMI (which we recommend connecting directly to the console), hidden in the casing, we practically have five inputs in full 2.1 standard. Let’s also add support for high refresh rates – 120 Hz at 8K and even 240 Hz at 4K – and we get a television that not only keeps up with the new consoles but also feels ready for consoles that are not yet available.