LG OLED C4 vs SAMSUNG S90F (WOLED)

The results of HDR materials are definitely among the better ones. Practically every film significantly exceeds the 700 nits barrier, allowing for a very realistic image. Of course, none of them surpasses the magical thousand, yet the combination of such results and unlimited contrast and black effectively boosts the outcome optically. The last of the scenes, featuring a full-screen burst of sunlight, is actually less bright than the others, although it still represents a commendable level. It is also worth mentioning the excellent coverage of the DCI-P3 colour palette, which will allow for achieving extremely vivid colours.

Does the S90F handle not only black, but also bright parts of the image? Definitely yes. Tales of OLEDs as “dark screens” can slowly be regarded as a myth. The Samsung S90F, like the LG C5 based on a very similar panel, achieves brightness exceeding 1000 nits. This is a value entirely sufficient to enjoy impressive and dynamic HDR imagery – both in films and series. Most of the scenes we tested look superb, with well-defined highlights and high contrast. Of course, OLED technology still has its limitations – in very bright, full-screen sequences, such as the test pattern from the film The Meg (picture 5), the television may noticeably dim the image. However, it should be emphasized that such scenes are rare. It can be considered that the HDR effect is good enough that even mid-range OLED models like the S90F can provide a cinematic experience in the home living room.

The best factory mode implemented in the tested television was "Filmmaker". It was this mode that we used during all tests. This mode proved to be quite good in terms of colour reproduction; however, other shortcomings effectively detracted from the enjoyment of viewing. Starting with the most basic aspect, the white balance, it was easy to notice that it was marked by a dominance of red, which overall changed the characteristics of the image. We could thus see a strong yellowing of the whites and a shift of all colours towards warmer shades. The gamma, which is a curve just as important, if not more so, was quite significantly lowered, resulting in a considerable drop in contrast, except at the beginning of the graph, where the television insidiously lost details. That’s all regarding SDR materials. Taking a closer look at films with a wide dynamic range, we can observe exactly the same phenomenon of yellowing of the white balance as in films with a standard colour palette. The EOTF curve, which replaces our gamma curve, is practically perfect and cannot be faulted.

The Samsung S90F, like most modern televisions, offers many picture modes, but – in line with our testing tradition – we assessed it in the best one, which is the Filmmaker mode. This way, the image looks significantly more natural than in the default, often oversaturated settings. It was neither overly saturated nor artificially muted – just closer to what should be seen. Of course, "more correct" does not mean "ideal". Unfortunately, our S90F unit had considerable issues with white balance, especially in the blue range, resulting in a slightly yellowish filter being applied to most scenes. Someone might say it looks more "cinematic" – because it is warmer – but let's not kid ourselves, George Lucas did not film Star Wars in sepia 😉 (you will find the comparison with the scene as always below).

Additionally, in HDR materials, there was a noticeable issue with brightness management. The EOTF curve showed a clear "spike" in brightness – the television brightened the image more than it should have, which made some effects look overly intense and diverged from the reference. Fortunately, some of these problems can be eliminated through professional calibration – you will read about its effects later in the review.

As we mentioned earlier, LG televisions are equipped with advanced tools for carrying out the calibration process. We therefore used them to model the image in the way that the director intended. And without modesty, we must admit that we achieved this phenomenally. Both SDR and HDR materials present a level that clearly indicates that this is how a film should look. It is worth looking at the colour errors on the "ColorChecker" palette here, where practically none of them exceeds "1", apart from two samples.

After calibration, we managed to eliminate practically all the previously mentioned errors. Older films in SDR quality finally look as they should – without the sepia effect or artificial aging of the image. The atmosphere of the classics returns to its rightful place (you’re welcome, Star Wars fans), and the colours no longer resemble an Instagram filter.

One of the key changes was also the improvement of brightness characteristics in HDR content. We managed to control the EOTF curve in almost a reference manner. Yes, the most demanding users may spot minimal deviations in brightness, but honestly – most viewers won’t even notice that. And it's no wonder, because the vast majority of errors are below a ΔE value of 3, which is below the threshold of visibility. After calibration, the S90F (WOLED) truly becomes an excellent display – one that provides nearly perfect picture quality.

Once again, we will take a look at the function responsible for smooth gradation, but we will also address the one that aims to improve the quality of lower-quality materials. The default smoothing of tonal transitions, as we have seen, was not the worst, but it can still be improved. The function has a slider, which allows us to adjust its strength. We recommend using the first one, as it yields very good results and does not blur important details.

Image scaling in 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. Admittedly, there are jagged edges on the trees, but this is not a major issue compared to other manufacturers.

Digital Image Processing in the S90F:

Fortunately, Samsung, as in most of its models, effectively manages the unwanted posterisation effect in the S90F. The feature responsible for this aspect is noise reduction, which does a decent job of smoothing tonal transitions and eliminating unnatural colour connections – of course, within its limitations. Unfortunately, it operates rather aggressively, so using it comes with compromises. In addition to improving gradation, it can also remove film grain or gently soften facial features. In this case, the choice is yours – do you prefer a more "clean" image, or do you want to preserve the original texture of the material?

Image Scaling in the S90F:

In this year's model, Samsung implemented its own AI processor – NQ4 Gen3, which does quite well with upscaling. In our test scenes, the television effectively "pulled up" lower quality towards artificial 4K – the image was more pleasant to view, and the differences in sharpness between native and scaled content were minimal. Unfortunately, behind all this AI marketing facade lies a certain shortcoming. The S90F struggles with overscan. If you reach for truly archival materials – e.g. a VHS tape of your parents' wedding – you must expect that the lower part of the image may be cut off. The image adaptation function to resolution simply does not work here as it should.

The maximum refresh rate that we can set on the LG G4 is 144 Hz. Naturally, this is only possible when connecting the television to a very powerful PC. In other cases, we will be operating at a maximum refresh rate of 120 Hz, which is recommended if we primarily want to watch sport or content with a lot of motion dynamics. For those requiring high fluidity of the image, the manufacturer has implemented a multi-step 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 within a range from 0 to 10, with each degree affecting the degree of smoothing, allowing everyone to find their golden mean.

The LG OLED C4 panel features an average response time of less than 1 ms (which directly results from our measurements), allowing for an incredibly clear image that is unattainable for LCD televisions, whose response times can be as high as several milliseconds. This is clearly visible in the pictures from the "UFO Test," showing no trailing blur behind the object.

The S90F really handles motion excellently – after all, it’s an OLED with a 144 Hz panel, so sports and games look absolutely stunning on it. The image is fluid, clear, and there’s no room for any ghosting or blurring that sometimes plagues cheaper LCDs.

The television is also equipped with motion smoothness settings, allowing you to customise everything to your preference. We have motion blur reduction and judder reduction – you can set it so that the image is super smooth (even to that soap opera effect), or more cinematic, with the classic 24-frame 'choppiness'. The choice is yours; Samsung doesn’t impose anything.

We can already say that LG C4, like practically every OLED television from the manufacturer, is exceptionally good in terms of compatibility with consoles and PCs. Thanks to the implementation of four full bandwidth HDMI 2.1 ports at 48 Gbps, the manufacturer has included all features that enhance the gaming experience, among which we find simultaneous support for FreeSync and G-Sync technology. With such a tandem, gamers with a graphics card from AMD or Nvidia can confidently opt for C4. However, what should delight the players requiring the highest possible quality the most is the simultaneous implementation of HDR Dolby Vision and HGIG mode. The first is particularly important as it works with extremely low input lag in all settings.

A standard in the Korean manufacturer's televisions is also the implementation of GameBar, allowing for quick adjustments of settings "on the fly" without the need to exit the game. It also enables image adjustments for visually impaired individuals, which is a very nice touch. Another important piece of information is that when VRR technology is enabled, we will not experience a drop in contrast. This is, of course, due to the panel's design and the absence of conventional backlighting. However, it is 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 of the manufacturer's OLEDs equipped with high refresh rate panels and HDMI 2.1 ports, creates a harmonious whole with consoles. In practice, it is a complete television, and if we expect the highest possible performance in gaming, C4 will be an ideal choice.

When it comes to gaming features – the S90F has absolutely nothing to fault. Aside from the lack of Dolby Vision, which is already the norm for Samsung. The television operates at 144 Hz, has four HDMI 2.1 ports, so you can easily connect more than one console or PC. Onboard, we also find the Game Bar – a practical tool that allows you to quickly glance at picture settings, VRR status, ALLM mode, and other useful options. Game Motion Plus also deserves a mention – Samsung's proprietary motion enhancer that is the only one truly functioning sensibly in games. The image appears smoother, but without any artificial effects or slowdowns.

It is also worth mentioning the HGiG feature, which – much to our slight surprise – works correctly. We're mentioning this because Samsung clearly broke something in one of the last updates, and in some models, the option responsible for HGiG simply... disappears from the menu. Setting it up becomes practically impossible. Fortunately, our S90F unit did not have this issue, but the situation is dynamic, so it's worth keeping this in mind and regularly checking for updates and information from the manufacturer.