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 also very important – because this is exactly the level of luminance around which most HDR content is now created on streaming platforms. The image finally has the right “glow,” and details in bright areas look as they should even without the use of dynamic metadata. However, there are scenes where the C5, like most OLED televisions, has some issues. Especially when the screen needs to illuminate fully. In our test sequences, such as the bright scene from the movie The Meg, brightness clearly decreases. Don’t get us wrong, this result isn’t bad; it’s more of a reminder that OLED technology still has its limitations. They are getting smaller year by year, but still.

Now, what about the colors? They are very good. Although the C5 does not match the OLEDs with QD-OLED or Tandem RGB panels, the DCI-P3 coverage at 97% and 73% BT.2020 will satisfy even the most demanding viewers. The colors are saturated, natural, and very consistent in HDR materials.

The Samsung QN990F belongs to the bright televisions and this is immediately evident in the tests. In measurements, it achieved around 1300 nits, which in practice allows you to enjoy movies as their creators intended. Bright scenes have the right impact, lights shine, and the feeling is truly cinematic. In standard test patterns, sequences number 1, 3, and 5 performed the best – there the brightness remained around 800-1000 nits, and the image looked very natural. In more challenging segments, it could drop to about 600 nits, but still the level remained sufficient for details to be well visible. However, it should be added that with such highly contrasted shots, the halo effect returns – the same one we mentioned regarding the blacks. Bright elements can leave a glow on dark backgrounds, and this is immediately noticeable. Since we are dealing with a QLED, the color palette is expanded and the colors look impressive. 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 results in a vibrant and attractive picture; however, competition in this and lower price segments can show even more.

LG C5, like other TVs we tested, was checked in the best possible factory mode – which remains Filmmaker Mode. And here we have good news: in SDR materials, LG once again did a solid job. The white balance and color reproduction straight out of the box are at a very high level. Most errors – both in balance and in the color 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 are something we would like to see in many more TVs!

However, the situation is different for HDR content, which is really what the C series was created for. Here the C5 performs weaker. The excessive presence of blue in the white balance causes the image to appear noticeably cooled – which affects, for instance, unnaturally pale skin tones and somewhat shifted tonality of the entire scene. Fortunately, LG provides very precise calibration tools, and we – as always – took advantage 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 was with white balance. Due to too little blue and also incorrect proportions 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 issues with brightness management – the television had difficulty maintaining details in the smallest parts of the image, mainly due to the way it controls the backlight zones. Fortunately, Samsung offers a lot of room for adjustment when it comes to setting corrections. We know that with proper calibration, you can definitely get a lot more out of this screen.

We must honestly admit – in the case of the LG C5, it took really very little to achieve an almost perfect picture. After calibration, we managed to achieve compliance with reference screens at a level that impresses even compared to much more expensive models. The picture after our adjustment looks exactly as filmmakers and series creators would want it – without color distortions, with natural depth and subtle texture. LG has done a great job this year regarding factory settings and calibration potential. Hats off!

After performing calibration, we managed to bring the white balance into order and eliminate the previous deficiencies in blue tones. As a result, the image no longer appeared as if it had a slightly yellowish filter – whites are cleaner, and the overall presentation looks much more natural. We also managed to some extent to tame the brightness characteristic in HDR content. The television now handles maintaining details in blacks significantly 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 emphasize details in dark scenes 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 completely eliminate. Nevertheless, after calibration, the image looks much more natural, primarily due to the correct exposure of white light. The final effect is definitely more pleasant to receive and closer to what we expect from a flagship television.

LG C5 handles lower-quality materials really well. One of the main issues older WOLEDs faced was posterization – unwanted "steps" in color transitions. The C5 uses a system feature to smooth these transitions, which works surprisingly effectively. The banding effect is almost completely eliminated, and the image gains consistency. Compared to last year's model, we feel that this feature works slightly weaker – but the good news is that it does not compromise the structure of the image. Film grain, textures, and details remain on the screen – nothing is smoothed out forcefully.

The C5 also does a great job of enhancing the quality of older recordings. Thanks to the α9 Gen6 processor (8th gen), "scaling to 4K" performs really solidly. The image is clear, the details are sharp, and the only minor drawback might be slightly visible jaggedness on some edges. However, there is no issue with overscan here – the image is not artificially cropped or shifted, which is a significant plus and still isn’t a given.

The QN990F deserves the highest praise for its upscaling. The processor responsible for "pulling up" classic TV to 8K resolution performs quite well. While watching content in a 576p signal, we had no illusions that we would suddenly see a marketing-style miracle where the image magically transforms into crystal-clear 8K. Nevertheless, the final effect was surprisingly good; the image looked clean and clear. It's just unfortunate that the TV, like most Samsung models, has an overscan issue, which slightly cuts off the edges of the screen on the left side.

Regarding image processing, Samsung provides a feature called "noise reduction," which in theory should improve tonal transitions in older materials, where they are usually more noticeable. Unfortunately, we felt quite disappointed here. The feature works poorly – it struggles with unwanted bands and can even introduce its own artifacts. On the plus side, the TV does not eliminate film grain when using this feature, but in practice, that's little consolation since the noise reduction itself proves to be practically useless.

The LG C5 is equipped with a 144 Hz panel, and this, combined with the practically 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 as sharp as a razor.

And what about movies in 24 frames? LG thought of that too. The built-in "TruMotion" smoother allows you to adjust the image to your own preferences. The "de-judder" slider increases the smoothness in movies, while "de-blur" gently reduces blurring – although to be fair, it is almost imperceptible here anyway.

The QN990F can easily be called one of the fastest televisions in the world. In 4K mode, it can display 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 8K signals at 120 Hz – and it performs very well here too. Motion remains smooth, and the television manages without a hitch even with the most demanding content. Additionally, there is a motion smoother, called "Picture Clarity." With it, you can adjust the image to your own preferences – leave a slight cinematic stutter or switch to maximum smoothness, which works great, for instance, in sports broadcasts.

LG C5 is a television designed with gamers in mind – and there’s not a hint of exaggeration in that. It's hard to find anything to criticize here. We have 144 Hz refresh rate, full support for VRR, ALLM, and up to four HDMI 2.1 ports with 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 limits, everything can be connected without any hassle.

The HDR configuration for gaming is also problem-free. The television properly supports the HGiG mode, which allows for an image consistent with the creators' intentions. For those interested, there’s also Dolby Vision in Gaming mode, though we still recommend HGiG as the most predictable and “pure” version of HDR for games.

The Game Bar is also included, which serves as the “command center” for the gamer. Everything that’s most important, from VRR settings, to picture modes, to frame rate information – is at our fingertips. The interface is simple and readable. 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 every gamer.

It must be said directly – the QN990F is one of those TVs that screams it was designed with gamers in mind. Samsung has been developing its gaming solutions for years, but here we have a true package. Sure, the lack of Dolby Vision support in games is a downside that will always come up in discussions. However, apart from that, the list of features is truly impressive. To start, we have Game Bar – a handy menu that allows you to quickly check and change game-related settings. You can see, for example, VRR is turned on, the frame rate, or the aspect ratio settings. It's like a small "dashboard," allowing you not to dig deep into the menu to make adjustments. Speaking of VRR: yes, variable refresh rate is present here and works flawlessly. Additionally, there's ALLM, which automatically switches the TV 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 number of ports makes the biggest impression. Four wireless HDMI 2.1 ports are already great news because you don't have to choose whether to connect the console, the receiver, or maybe even the PC. There's plenty of room here for everything. And if we add an additional micro HDMI (which we recommend connecting directly to consoles), hidden in the housing, we practically have five inputs in full 2.1 standard. Add to that support for high refresh rates – 120 Hz in 8K or even 240 Hz in 4K – and we get a TV that not only keeps up with the new consoles but also feels ready for consoles that are yet to come.