LG OLED C5 vs Samsung QN990F

LG C5 has finally done what we've 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 very important – because most HDR content on streaming platforms is created around such luminance today. The image finally has the right "glow," and 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 TVs, has certain issues. Especially when the screen has to light up entirely. In our test sequences, like the bright scene from the movie The Meg, brightness noticeably drops. Don't get us wrong, this result is not bad; it’s more of a reminder that OLED technology still has its limitations. Year by year, they are getting smaller, but they still exist.

Now, what about the colours? They are very good. Although the C5 doesn't match OLEDs with QD-OLED or Tandem RGB panels, its coverage of the DCI-P3 gamut at 97% and 73% of BT.2020 will satisfy even the more demanding viewers. The colours are saturated, natural, and very consistent in HDR materials.

Samsung QN990F is one of the bright televisions, and this is immediately apparent in tests. In measurements, it achieved around 1300 nits, which in practice allows you to enjoy films as their creators intended. Bright scenes have the right strength, lights shine, and the impression is truly cinematic. In standard test patterns, sequences number 1, 3, and 5 performed the best – there, brightness remained around 800-1000 nits, and the image looked very natural. In more difficult segments, it could dip to around 600 nits, but the level was still sufficient for details to be clearly visible. However, it should be added that with such highly contrasted shots, the halo effect returns – the same one we mentioned regarding blacks. Bright elements can leave a glow on dark backgrounds, and this is immediately noticeable. As we are dealing with a QLED, the colour palette is expanded, and the colours present themselves impressively. The problem is that with such a flagship model, we expected better numbers. 91% coverage of DCI-P3 and about 67% BT.2020 are results that can be considered solid but not outstanding. This gives an image that is vibrant and appealing; however, the competition in this and lower price ranges can show even more.

LG C5, like other TVs we tested, was 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 Checker test – did not exceed a ΔE value of 3, which is the threshold above which differences become visible to the naked eye. Such factory settings are what we'd like to see in many more TVs!

However, the situation is different for HDR content, which is what the C series was truly designed for. Here, the C5 performs weaker. An excessive amount of blue in the white balance causes the image to appear distinctly cooler – which affects things like unnaturally pale skin tones or somewhat shifted tonality 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 out-of-the-box setting available. Right from the start, we noticed a few significant issues. The biggest problem was with white balance. Due to too little blue, as well as incorrect 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 noticed problems with brightness management—the TV struggled to maintain details in the smallest parts of the image, mainly due to how it manages backlight zones. Fortunately, Samsung provides plenty of room for adjustment when it comes to setting corrections. We know that with proper calibration, much more can be extracted from this screen.

We must honestly admit – in the case of the LG C5, it took very little to achieve an almost perfect image. After carrying out calibration, we managed to achieve compliance with reference screens at a level that impresses even compared to significantly more expensive models. The image after our adjustments looks exactly as filmmakers and series creators would want – with no colour distortion, natural depth, and subtle plasticity. LG has done a great job this year regarding factory settings and calibration potential. Hats off!

After carrying out the calibration, we managed to bring the white balance into order and eliminate the earlier shortcomings in shades of blue. As a result, the picture no longer looked like it had a slight yellowish filter – the whites are cleaner, and the whole thing presents itself much more naturally. We also managed to tame the brightness characteristic in HDR content to some extent. The television now handles maintaining detail in blacks much better and does not lose them as much as before. However, when we look at the EOTF curve and how 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, how it is managed by the QN990F, which is practically impossible to eliminate completely. Despite this, after calibration, the picture looks significantly more natural, mainly due to the correct exposure of white light. The final effect is definitely more pleasant to the eye and closer to what we expect from a flagship television.

LG C5 handles lower quality materials exceptionally well. One of the main issues that older WOLEDs faced was posterisation – unwanted “steps” in colour transitions. The C5 utilises a system function that smooths these transitions, and it works surprisingly effectively. The banding effect is nearly completely eliminated, and the image gains consistency. Compared to last year's model, we feel that this function operates slightly weaker – but the good news is that it doesn't compromise the image structure. Film grain, textures, and details remain on the screen – nothing is forcefully smoothed out.

The C5 also excels at enhancing the quality of older recordings. Thanks to the α9 Gen6 (8th gen) processor, "scaling to 4K" is impressively solid. The image is clear, details are sharp, and the only minor drawback might be a slightly noticeable aliasing on some edges. However, there is no problem with overscan here – the image is not artificially cropped or shifted, which is a significant plus and still not a given.

The QN990F deserves the highest praise for its upscaling capabilities. The processor responsible for 'lifting' classic TV to 8K resolution does a really decent job. Watching footage in 576p, we had no illusions that we would suddenly see a miraculous transformation like in an advertisement, where the image magically turns into crystal-clear 8K. Nevertheless, the final effect was surprisingly good; the picture looked clean and sharp. It's just a shame that the TV, like most Samsung models, has an overscan issue, which slightly cuts off 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 noticeable. Unfortunately, here we felt quite disappointed. The feature performs poorly – it struggles with unwanted banding and can even introduce its own artifacts. On the plus side, it’s worth noting that the TV doesn’t remove film grain when using this feature, but in practice, that’s a poor consolation when the noise reduction itself turns out to be practically useless.

The LG C5 is equipped with a 144 Hz display, and this, combined with 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 has 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” subtly reduces motion blur – although to be honest, it’s practically invisible here.

QN990F can easily be called one of the fastest TVs in the world. In 4K mode, it can display images at a frequency of up to 240 Hz, which until now was more associated with gaming monitors than with living room TVs. However, in everyday viewing, what's more important is how it handles an 8K signal at 120 Hz – and it performs very well here too. Motion remains smooth, and the TV handles even the most demanding content without breaking a sweat. Additionally, there's the motion smoother, or "Image Clarity." Thanks to this, you can adjust the picture to your preferences – leave it slightly cinematic with a bit of judder or switch to maximum smoothness, which works brilliantly for things like sports broadcasts.

LG C5 is a TV designed with gamers in mind – and there's not 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 full bandwidth of 48 Gb/s. For those who have an Xbox, PS5, Nintendo, and a gaming PC in one room – no limitations, everything can be connected without any hassle.

Configuring HDR for gaming is also straightforward. The TV correctly supports the HGiG mode, which allows you to achieve an image that aligns with the creators' intentions. For those interested, there is also Dolby Vision in the Gaming version, although we still recommend HGiG as the most predictable and "clean" variant of HDR in games.

It also includes the Game Bar, which is a "command centre" for the gamer. Everything important, from VRR settings, picture modes, to frame rate information – is at our fingertips. The interface is simple and clear. It may look like something out of a space simulator, but it serves its purpose and just works; exactly as it should.

C5 is truly a complete package for any gamer.

It has to be said straightforwardly – the QN990F is one of those televisions that scream they were designed with gamers in mind. Samsung has been developing its gaming solutions for years, but here we have a true package. 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 truly impressive. To start, we have the Game Bar – a handy menu that allows you to quickly check and change game-related settings. You can see things like VRR enabled, frame rate, or aspect ratio settings there. It's like a little “dashboard” so you don’t have to dig deep into the menu to fix something. Since the word VRR was mentioned: yes, variable refresh rate is present here and works flawlessly. Plus, there's ALLM, which automatically switches the television to game mode as soon as the console is turned on. These may seem like small details, but together they make using the QN990F simply convenient and hassle-free.

However, the greatest impression comes from the number of ports. Four wireless HDMI 2.1 ports as standard is already great news, as there's no need to choose whether to connect the console, the receiver, or maybe even the PC. There's comfortably enough room for everything here. And if we add another micro HDMI (which we recommend connecting directly to the console), hidden within the casing, then in practice we have five inputs in full 2.1 standard. Let’s also add support for high refresh rates – 120 Hz in 8K or even 240 Hz in 4K – and we get a television that not only keeps up with the new consoles but also feels ready for consoles that aren’t even out yet.