LG OLED C4 vs Samsung OLED S90D / S94D (WRGB OLED)

The HDR performance of the LG OLED C4 is impressive, firmly placing it in the higher tier. Most films exceed 700 nits, delivering a highly realistic image. While none surpass the 1,000-nit mark, the combination of these results with the TV’s infinite contrast and perfect blacks significantly enhances the visual experience. The final scene, with a full-screen flash of sunlight, is slightly less bright than the others but still maintains a solid level of brightness. Another highlight is the excellent DCI-P3 colour gamut coverage, which ensures incredibly vibrant colours. The HDR technology in the LG OLED C4 delivers exceptional colour and detail reproduction. The dynamic tone mapping feature optimises brightness levels, ensuring ideal light reproduction in every scene, even in the most demanding high-dynamic films.

The Samsung S90D demonstrates impressive brightness performance in the tested film scenes, surpassing the 1000 nits mark in the first four shots—an outstanding result for an OLED display. In the final shot, which features a fullscreen flash of sunlight, the brightness dips to around 500 nits. While this is a decrease, it remains within a very good range, ensuring visibility and detail retention even in bright scenes.

Another key highlight of the Samsung S90D is its remarkable colour coverage, achieving 98% of the DCI-P3 colour space. This means the TV can reproduce an exceptionally wide range of colours, contributing to vivid and lifelike images that are particularly beneficial for films, high-quality video, and HDR content. The high colour accuracy and impressive brightness capabilities, makes the S90D an ideal choice for users seeking premium image quality across various lighting environments, whether in darker rooms or bright, sunlit spaces.

The best factory mode on the tested television was "Filmmaker," which served as the basis for all evaluations. In terms of colour reproduction, this mode performed reasonably well; however, certain flaws significantly detracted from the overall viewing experience. The most fundamental issue was the white balance, which exhibited a noticeable dominance of red, skewing the image characteristics. This resulted in a pronounced yellow tint to whites and a general shift of all colours towards warmer tones.

The gamma, an equally crucial—if not more important—aspect, was notably lowered, leading to a marked reduction in contrast. Additionally, the television frequently lost detail at the start of the gamma curve. These issues were most apparent in SDR content.

When examining HDR materials, the same yellowing effect in the white balance was observed, as seen with SDR content. However, the EOTF curve, which replaces the gamma curve for HDR, was near perfect and left little room for criticism.

The S90D was tested in Filmmaker mode, which provides good colour reproduction, albeit with some imperfections that may be noticeable to more discerning users. This mode might appear overly warm, and those switching from Standard mode could find the change somewhat jarring. It is important to note that this issue stems from suboptimal settings, such as the white balance, rather than the Filmmaker mode.

In both SDR and HDR content, the device shows a drop in blue tones, resulting in colours appearing warmer than intended. In practice, this means that certain shades, such as sky blue or skin tones, may seem less natural, with a slight pink or yellow tint. The Colour Checker test confirms these deviations, indicating a shift towards warmer hues. In SDR content, the gamma chart reveals slight inconsistencies that make the image appear marginally darker, particularly in shadowed areas, which may obscure finer details in darker scenes.

In 4K HDR content, the EOTF curve exceeds the recommended level, leading to an overly bright display in some parts of the image, which can cause highlights to appear blown out. Overall, the Samsung S90D delivers a solid image straight out of the box, but for the best performance, further calibration is advised, especially with more demanding content.

As mentioned, LG televisions come with advanced tools to facilitate an accurate calibration process. By utilising these tools, we meticulously adjusted the image to align with the director’s original vision. Without overstating, the results were outstanding. Both SDR and HDR content now achieve a level of visual fidelity that reflects how films are intended to be seen.

Examining the colour accuracy on the "ColourChecker" palette reveals impressive results, with almost all colour errors falling below a delta of "1," aside from two minor exceptions. Post-calibration, the LG OLED C4 demonstrated a marked improvement in colour reproduction, particularly in SDR and HDR modes. Testing the TV after calibration highlighted its capacity for delivering exceptionally accurate colours, underlining the high calibre of this model. The LG C41LA offers a stunningly precise colour palette, sure to satisfy even the most discerning viewers.

After calibration, the Samsung S90D in movie mode exceeds expectations. The white balance for HD and 4K HDR content has been refined to near perfection. While minor imperfections remain, they are so subtle that they don’t significantly impact the overall image quality. The colours are now more balanced, resulting in a natural reproduction of details, particularly in scenes requiring an accurate colour palette. It’s important to note that this model, in this size, uses a WOLED panel, which has a smaller wide colour gamut coverage and doesn't deliver the same vibrant colours as the 65-inch version with its QD-OLED panel.

The contrast has also seen notable improvements. Following calibration, the gamma curve now closely aligns with the expected line, achieving a better balance between the bright and dark areas of the image. The EOTF curve, which previously exhibited issues with overexposed scenes, now produces more accurate results, allowing for improved detail retention in the brighter parts of the image, especially in HDR content.

Let us revisit the function responsible for smooth gradation and consider its role in improving lower-quality materials. The default smoothing of tonal transitions, while decent, can be further enhanced. The feature includes a slider for adjusting its strength, and we recommend selecting the first option. This setting strikes a balance, offering excellent results without compromising important details through unnecessary blurring.

The image scaling on the LG C4 is commendable, though not entirely without flaws. By default, the image appears slightly sharper, though not to an intrusive degree. While jagged edges on elements like trees are occasionally visible, this issue is relatively minor compared to similar offerings from other manufacturers.

The S90D TV handles tonal transitions exceptionally well. Thanks to advanced technology, the transitions between colours are smooth and natural. The noise reduction function can further enhance the smoothness of tonal shifts, which is particularly useful in certain situations. However, it's important to note that enabling noise reduction can also blur the natural film grain, diminishing the cinematic quality of the image. For this reason, it’s advisable to use this function with caution, as preserving the natural grain can enhance the character and authenticity of the content being watched.

As always, Samsung excels in image scaling from lower resolutions. The S90D effectively processes lower-resolution content, delivering a clear and accurate picture. The model’s outline is crisp, ensuring the image looks natural and detailed. Even the finer details, such as tree branches, are well-rendered without visible jagged edges that could degrade image quality. Thanks to its effective scaling, the S90D ensures that even lower-resolution content looks appealing, satisfying users who enjoy a wide range of content sources, such as regular broadcast or cable TV.

The LG G4 supports a maximum refresh rate of 144 Hz, achievable only when connected to a high-performance PC. Otherwise, the television operates at a maximum of 120 Hz, the recommended setting for viewing sports or content with fast-paced motion. For those prioritising smooth image quality, LG has included a versatile motion smoothing feature called "TrueMotion." This function is split into two adjustable sliders: De-Blur, which sharpens moving images, and De-Judder, which reduces jitter. Both sliders offer a range of settings from 0 to 10, enabling users to fine-tune the motion smoothness to their preference.

The LG OLED C4 boasts an impressive average response time of less than 1 millisecond, as confirmed by our measurements. This results in exceptional image clarity, far surpassing LCD televisions, which often have response times of several milliseconds. This clarity is evident in tests like the "UFO Test," where no trailing blur is visible behind moving objects.

The Samsung S90D television features a 120 Hz panel, with the option to "overclock" to 144 Hz when connected to a compatible PC, offering exceptional motion smoothness. Samsung has long provided a range of image sharpness settings on a ten-point scale, allowing users to tailor the display to their preferences. In the UFO test, the OLED panel shows no signs of blurring, with pixel response instantaneous and effectively capturing dynamic movements. OLED technology is renowned for its performance in this regard, making it one of the best options on the market. The image remains incredibly sharp and detailed, even during fast-paced action, making the S90D an excellent choice for gamers and sports enthusiasts alike.

The LG C4, like nearly all OLED televisions from the manufacturer, excels in its compatibility with consoles and PCs. With the inclusion of four full-bandwidth HDMI 2.1 ports supporting 48 Gbps, the TV incorporates a range of features to enhance the gaming experience. Notably, it offers simultaneous support for FreeSync and G-Sync, making it an ideal choice for gamers using AMD or Nvidia graphics cards. For those seeking the best possible gaming quality, the integration of HDR Dolby Vision and HGIG mode is particularly impressive. HDR Dolby Vision operates with remarkably low input lag across all settings, ensuring smooth and responsive gameplay.

A standout feature in LG's televisions is the GameBar, which allows users to adjust settings in real-time without leaving the game. This includes options for customising the image for viewers with visual impairments, a thoughtful addition. Additionally, enabling VRR (Variable Refresh Rate) does not result in a loss of contrast—a benefit of the OLED panel's self-emissive technology, eliminating the need for conventional backlighting. While some slight flickering of grey tones may occur, this is a characteristic of VRR technology across all manufacturers.

In summary: The LG C4, like the brand's other OLED models equipped with high-refresh-rate panels and HDMI 2.1, provides a seamless and immersive gaming experience. For gamers demanding top-tier performance, this TV is an outstanding choice.

The Samsung S90D is an ideal choice for gamers, featuring four HDMI 2.1 ports that support key gaming technologies such as Auto Low Latency Mode (ALLM), Variable Refresh Rate (VRR), and HDR Gaming Interest Group (HGIG). These features ensure smoother and more responsive gameplay, greatly enhancing performance during intense gaming sessions. The TV also includes a dedicated Game Bar, which makes managing game settings easy. This functionality allows users to quickly adjust parameters like the aspect ratio offering flexibility for different games and gameplay styles. Customising preferences is straightforward, further enhancing the convenience and enjoyment of gaming.

For PC users, the TV impresses by supporting a refresh rate of 144Hz when connected to a computer. Users with Nvidia or AMD graphics cards can also use G-Sync and FreeSync for a smoother gaming experience. However, it’s important to note that the TV does not support Dolby Vision, which may be a drawback for some. That said, Dolby Vision is not as widely adopted in gaming as in film, so this may not be a significant concern for most gamers. Overall, the S90D offers exceptional features for gamers, making it an excellent choice for those seeking outstanding image quality and modern technological solutions.