LG OLED C4 vs Samsung QN90F / QN92F

The results of HDR materials are definitely among the better ones. Practically every film significantly exceeds the 700 nits barrier, which allows for a very realistic image. Of course, none of them surpasses the magical thousand, however, the combination of such results along with unlimited contrast and black effectively boosts the visual outcome. The last of the scenes, featuring a fullscreen sun burst, is indeed less bright than the others, although it still represents a respectable level. It's also worth mentioning the excellent coverage of the DCI-P3 colour palette, which will enable the achievement of exceptionally vivid colours.

Samsung QN90F can really shine with brightness. In our measurements, it reached even over 2200 nits, which directly translates to the viewing experience. In practice, this means that when a very bright scene appears in a film – for example, a sunrise in The Meg – the screen looks as if natural light is actually shining on us. This isn't just a number from a table, but a real sense of image intensity! However, the TV can't always deliver its full power. With smaller details, such as spotlights or lamps, brightness drops to 500–700 nits. This is a deliberate decision by the algorithms – by doing this, the contrast between large and small elements is better controlled, and the image doesn't lose balance. Importantly, this is still a huge improvement compared to last year's QN90D, where similar details were almost invisible, shining at just 200 nits. Here, the HDR effect is much more cohesive and credible. The only downside is the colours. The coverage of the DCI-P3 spectrum has plateaued at 91%, which can be considered a rather average result in this price range.

The best factory mode implemented in the tested television was "Filmmaker". That was the one we used during all tests. This mode, in terms of colour reproduction, turned out to be quite decent, although other flaws effectively detracted from the enjoyment of the viewing experience. Starting with the most basic one, which is white balance, it was easy to notice that this was marked by a dominance of red, which completely altered the characteristics of the picture. We could see a strong yellowing of the whites and a shift of all colours to warmer tones. The gamma, which is a graph as equally important, if not more so, was quite severely reduced, resulting in a significant drop in contrast, except for the start of the graph, where the television insidiously lost details. That’s all regarding SDR materials. Looking closely at films with a wide dynamic range, we can observe exactly the same phenomenon of white balance yellowing as in films with a standard colour palette. The EOTF curve, which replaces the gamma chart for us, is practically perfect and cannot be faulted.

The colour reproduction in the QN90F was tested in Filmmaker mode and, as is usually the case with Samsung TVs, this mode proves to be the best starting point straight out of the box. However, this does not mean that we are dealing with an image free of flaws. The white balance in SDR and HDR content was surprisingly good – colours didn't drift in any direction and even in its factory settings it looked solid. However, a problem arose with the gamma and EOTF curves, which determine how the TV manages brightness. Here, the QN90F significantly brightened the entire image, causing the black levels and colours to lose their intensity, and the overall effect resembled that of an applied milky filter. Fortunately, Samsung, unlike many competitors in the miniLED world, provides users with plenty of tools to control settings that we won't find in other manufacturers, such as Chinese brands. Therefore, we decided to see if we could squeeze the full potential out of the QN90F because we know that such a high series is capable of much more.

As we mentioned earlier, LG televisions are equipped with advanced tools for carrying out the calibration process. We used them to model the picture in line with what the director envisioned. And without modesty, we must admit that we achieved this phenomenally. Both SDR and HDR materials present a level that clearly indicates this is how a film should look. It's worth taking a look at the colour errors on the "ColorChecker" palette, where practically none of them exceed "1", except for two samples.

After our adjustment of the settings, the QN90F showed what it’s really capable of – and we have to admit, it’s one of the best images we’ve seen on a miniLED screen this year. As we mentioned earlier, the white balance wasn’t a big issue even in the factory settings, but it was only after gamma calibration that we were able to get close to reference values. The same goes for HDR content, where the EOTF curve post-adjustment presents mature and consistent results. Indeed, in some films, you can notice that the smallest elements of the image are slightly brightened, and with a limited number of local dimming zones, there's still a risk of halo effect. However, it’s important to remember that such phenomena are characteristic of all miniLED TVs and it’s difficult to expect miracles even from the QN90F. The most important thing is that after calibration, the television displays an image that confidently competes with many OLED screens available on the market in terms of expressing the director's vision.

Once again, we will take a look at the feature responsible for gentle gradation, but we will also address the one that aims to enhance the quality of lower-quality materials. The default smoothing of tonal transitions, as we could see, was not the worst, but it can be improved further. The function has a slider that allows us to adjust its intensity. We recommend using the former, as it produces very good results and does not blur important details.

Image scaling on LG C4 is quite good, however, it cannot be said to be without flaws. The image is slightly sharper by default, although not in a very noticeable way. While jagged edges of trees can be seen, it is not a major issue when compared to other manufacturers.

QN90F handles upscaling very well. Materials in lower resolutions, even SD, are enhanced to a clear and sharp image, where a lot of background detail can be seen. This is a big advantage, as the TV makes older content or everyday television look significantly better than on most budget screens. However, the issue of overscan remains, which is the cropping of the screen edges that cannot be turned off on Samsungs. This can cause some subtitles on the screen to disappear or Auntie's face from the wedding on a VHS tape to be slightly cropped. 😉

The digital image processing also performs well. In the menu, we find a feature called "noise reduction," which can smooth tonal transitions and improve the viewing of lower quality materials, such as those from YouTube. In the medium setting, the effect is most beneficial – it doesn't heavily interfere with details while simultaneously eliminating the problem of "banding" in colours. However, it's worth noting that the feature can be quite aggressive and removes natural film grain in older movies, so it's best to use it sparingly.

The maximum refresh rate we can set on the LG G4 is 144 Hz. Naturally, this is only possible when connecting the TV to a very powerful PC. Otherwise, we will operate at a maximum refresh rate of 120 Hz, which is recommended if we primarily want to watch sports or content with a lot of motion dynamics. For those who require high fluidity of the image, the manufacturer has implemented a multi-level motion smoother called "TrueMotion". It has been divided into two separate sliders that adjust the sharpness of moving images (De-Blur) and judder (De-Judder). Both sliders can be set in the range of 0 to 10, with each degree affecting the level of smoothing, allowing everyone to find their sweet spot.

The panel of the LG OLED C4 features an average response time of less than 1 ms (which directly results from our measurements), enabling the achievement of an extremely clear image, unattainable for LCD TVs, which can have response times of up to several milliseconds. This is clearly evident in the images from the "UFO Test," which show no trailing blur behind the object.

QN90F has been equipped with a panel that has a maximum refresh rate of 165 Hz, and while this advantage will mainly be appreciated by PC gamers, it’s still worth highlighting. In movies or sports broadcasts, we are limited to the classic 120 Hz, but this is not a cause for concern. In practice, the additional motion smoother is more significant here. Thanks to the "Motion Clarity" setting, we can adjust the picture to our own preferences. The blur reduction option is responsible for fluidity and ghosting in sports. Meanwhile, the "judder reduction" function improves motion fluidity in productions recorded at 24 frames, namely films and series. If we set it high, the film looks smoother and more fluid than it was actually shot. Lower values, on the other hand, preserve its cinematic "rawness" with the visible film frame.

We can now say that LG C4, like practically every OLED television from the manufacturer, is exceptionally good in terms of cooperation with consoles and PCs. Thanks to the implementation of four full-bandwidth HDMI 2.1 ports at 48 Gbps, the manufacturer has embedded all the features that enhance gaming comfort, including simultaneous support for FreeSync and G-Sync technologies. With such a tandem, players with graphics cards from AMD or nVidia can safely choose C4. However, what should please gamers demanding the highest possible quality the most is the simultaneous implementation of HDR Dolby Vision and HGIG mode. The former is particularly important as it operates with extremely low input lag in all settings.

A standard feature in televisions from the Korean manufacturer is also the implementation of GameBar, allowing for quick adjustments of settings "on the fly," without the need to exit the game. It also allows for image adjustments for people with visual impairments, which is an incredibly nice touch. Another important piece of information is that when VRR technology is enabled, we won’t experience a drop in contrast. This is, of course, due to the design of the panel and the absence of conventional backlighting. It is, however, normal for shades of grey to flicker slightly, although this is a characteristic feature of this function regardless of the manufacturer and television.

In summary: LG C4, just like all the manufacturer's OLEDs equipped with high-refresh-rate panels and HDMI 2.1 connections, creates a harmonious whole with consoles. In practice, it is a complete television, and if we expect the highest possible efficiency in gaming, C4 will be an ideal choice.

QN90F has almost everything to become the perfect TV for gamers. Things like four HDMI ports, VRR, ALLM, or refresh rates reaching up to 165 Hz need no reminder. The Game Motion Plus mode deserves a big thumbs up, which is the proprietary motion smoothing technology for games. With it, you can add a few 'artificial' frames and make the image generated from the console look smoother than it should. This is a very unique solution in the world of TVs – competing systems usually do not offer this – and that's why Samsung has had a strong selling point among gamers for years, even despite the lack of support for the still niche Dolby Vision in games.

[UPDATE] We have updated our tests of Samsung TVs from the 2025 range due to the release of firmware version 1131, which restored the crucial HGiG feature for gamers.

So why do we refer to it as an 'almost' perfect screen? Unfortunately, just like in recent Samsung models, we've noticed a problem with the lack of HGiG functionality. This is a solution that allows the TV to leave control over tone mapping to the console, so that games look exactly as the creators intended. Worse still, this feature was previously present and disappeared after software updates. Instead of minor fixes, we got a step backward. It's a shame, because if it weren't for this lack, the QN90F could have been a truly ideal choice for gamers in the miniLED category.