LG OLED C5 vs Samsung OLED S90F (QD-OLED)

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.

The biggest difference between the 65-inch S90F and the other versions is brightness. The QD-OLED panel can reach up to 1700 nits in laboratory tests, which is over 500 nits more than the version with a WOLED matrix. This translates to a significantly stronger and more immersive HDR effect. In most scenes, the bright parts of the image look stunning, and we must admit that we were positively surprised, as we expected results closer to the WOLED version, but what we got is an effect that impresses even in films. As with every OLED, there are moments when the panel must reduce brightness a bit. This mainly concerns full-screen, very demanding scenes – for instance, in the last test scene from the movie “The Meg,” brightness drops to around 800 nits. However, it's hard to consider this a flaw because it's still an excellent result, unprecedented in OLED TVs in this price range. Everything suggests that the 65-inch S90F could be one of the best choices this year for those looking for a strong OLED at a reasonable price. Another advantage of the QD-OLED matrix in HDR content is its colour gamut coverage. Thanks to quantum dots, the television achieves nearly 100% of the DCI-P3 gamut and almost 90% of the BT.2020 gamut. These are values that place it alongside much more expensive models and make it exceptional in its class.

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.

Samsung S90F, like most modern televisions, offers several picture modes, but in keeping with our tradition, we checked it in the most important one, which is Filmmaker. This setting makes the picture look much more natural than in the default, often oversaturated modes. It is neither overly vivid nor artificially dimmed – just closer to what you should actually see. However, this doesn’t mean it’s perfect. The S90F had noticeable shortcomings in white balance, particularly in the blue range, which created a slightly yellowish filter effect on most scenes. One might argue that it looks more “cinematic” because it’s warmer, but let’s not kid ourselves – George Lucas didn’t shoot Star Wars in sepia 😉 (you’ll find a comparison with a scene as always below). In HDR materials, there was also an issue with brightness management. The EOTF curve clearly showed that the television brightens the image more than it should, which led to some effects looking too intense and deviating from the reference. Fortunately, many of these flaws can be eliminated through professional calibration – we will discuss the effects of this procedure later in the test.

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!

Calibration quickly revealed that the S90F has a significant reserve of capabilities. The image in SDR immediately gained a natural quality – classic films no longer looked like someone was applying a yellowish filter, and the colours regained their proper character. It's a return to the atmosphere of the original, without the impression that someone tried to "age" it forcefully. In HDR content, the difference was even more pronounced. The EOTF curve was managed to nearly reference level, and any deviations are so subtle that most viewers wouldn't even notice them. In practice, the S90F shows an image very close to ideal post-calibration. Compared to the WOLED version, it even performs better – mainly due to a wider coverage of the colour palette, which makes the colours look fuller and more vibrant.

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.

S90F performs really well here, although there are some points that are common across most Samsung TVs. The noise reduction feature can effectively smooth out unwanted colour transitions in lower-quality materials like television or YouTube, making them look simply better. However, it should be noted that it works quite aggressively and can also soften elements that we wouldn’t want to alter, such as facial details. Therefore, if we want to use it, it’s best to use it in the "medium" setting and be aware of the compromise it brings. The upscaling itself is of a high standard – low-quality materials are pulled towards an image resembling 4K. The only caveat is that the S90F can still have issues with so-called overscan, meaning slight trimming of the edges in very low-quality materials such as 576p and lower.

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.

S90F is an OLED with a refresh rate of 144 Hz, but in practice, what matters most is how it performs at 120 Hz, as this frequency is the most important when watching sports. The QD-OLED panel is no different in this regard from WOLED panels – the pixel response is nearly instantaneous, so motion is rendered with surgical precision. The effect is easy to predict. The image is practically free of motion blur, making gaming on consoles, matches, or other sports broadcasts a tremendous pleasure on the S90F.

Fans of movies and series have not been forgotten either. Like every Samsung television with a refresh rate of 120 Hz and above, the S90F is equipped with a proprietary motion smoother called “Picture Clarity.” Here, we find two sliders – blur reduction and judder reduction – which allow you to improve the smoothness of content recorded at 24 frames and tailor the effect to your own preferences.

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.

The S90F is a television that genuinely brings a lot of joy when gaming. To start with, we get four proper HDMI 2.1 ports, which means you can connect all consoles and PCs without having to figure out which device takes priority. This is a convenient and practical solution, which is not at all a given with other manufacturers. Additionally, there are key features such as: automatic game mode (ALLM), which automatically switches the screen to low latency settings, and VRR frame synchronization that operates over a wide range from 48 to 144 Hz. This ensures the picture remains smooth, whether we're playing fast-paced online shooters or more relaxed narrative titles. The Game Bar also deserves attention – a panel that allows quick access to several handy extras. For example, you can turn on an extra crosshair in the middle of the screen, enlarge the minimap, or, in the case of PC, change the aspect ratio. Finally, there's also Samsung's unique Game Motion Plus mode. Its task is to smooth out older or poorly optimized titles, and it actually works quite well. With this mode, even less polished games can look better and provide more enjoyment than on other televisions that theoretically offer the same technical parameters.