Samsung QD-OLED S90D / S94D vs LG OLED C4

In the HDR effect category, the Samsung S90D delivers remarkable performance. On the luminance graph for up to 10% of the window, the television surpasses the 1000 nits mark, which is a notable achievement. However, in the film scenes we tested, these values were slightly lower. In scenes with fullscreen sun glare the brightness drops to about 500 nits, but this is still considered a very good result. It is also worth noting that this model stands out due to its very high colour gamut coverage, thanks to the QD-OLED panel, giving it an edge over televisions with WOLED panels, which cannot achieve such a wide spectrum of colours.

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 65" S90D with a QD-OLED panel has been tested in Filmmaker Mode, which the manufacturer has used for years to deliver optimal picture settings. In this mode, the TV offers a very good image, but there are some shortcomings worth noting.

In terms of white balance, viewers may notice a red dominance in HD content, which can make skin tones appear unnatural and create a warm overall scene, potentially affecting immersion. This issue becomes more apparent in scenes where subtle colour differences are important. The same effect can be observed in 4K HDR content, though the red shift is less pronounced. This shift can prevent certain details and colours from being fully realised, diminishing the naturalness of the image.

As for contrast, the gamma performance is decent but still has some issues. The gamma values fall short of the reference level of 2.4, resulting in bright areas of the image appearing washed out and dark areas lacking detail. This limitation can make certain scenes feel less dynamic and impact the depth and richness of the picture. However, the EOTF curve for contrast in 4K HDR content performs well, showing the TV's ability to handle differences in brightness. That said, these values still fall slightly below the ideal range, indicating room for further optimisation.

Overall, the Samsung S90D in Filmmaker Mode offers solid colour reproduction, but some adjustments are needed to fully unlock its potential, particularly with different types of content.

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 quality improves more than anticipated after calibrating the S90D television in movie mode. The white balance for HD and 4K HDR content has been fine-tuned to near perfection. While minor imperfections are still noticeable, they are subtle enough not to significantly impact the overall picture quality. Colours have become more cohesive, promoting a natural reproduction of details, particularly in scenes where precise colour representation is essential. It’s important to note that this particular model, in this size, uses a QD-OLED panel, which offers a broader colour gamut compared to other versions of this model equipped with a WOLED panel.

The contrast has also seen a marked improvement. After calibration, the gamma chart is much closer to the expected curve, resulting in a better balance between the bright and dark areas of the image. The EOTF curve, which previously indicated issues with overexposed scenes, now shows significantly better results. This improvement allows for greater preservation of details in the brighter parts of the image, particularly in HDR 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.

The television excels at smoothing tonal transitions, allowing colours to blend seamlessly, resulting in a natural and fluid image. The built-in noise reduction feature can further enhance these transitions, useful in certain situations. However, it is important to note that activating this option may overly smooth out the desired film grain structure, potentially compromising the authenticity and atmosphere of the image. Therefore, caution is advised when using this feature, to maintain the character and depth of the content.

The S90D model handles lower-resolution materials effectively, as demonstrated in the displayed image. The model's silhouette remains sharp and naturally reproduced, with fine details preserved. Additionally, the branches of the trees are well-defined, free from any visible jagged edges that might otherwise degrade the image quality. Thanks to efficient scaling, even lower-resolution content appears attractive on the screen, which is sure to please users who rely on a variety of content sources, such as standard cable or antenna television.

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, featuring a 120 Hz refresh rate matrix and up to 144 Hz in the appropriate PC configuration, delivers excellent motion fluidity. Samsung highlights a range of sharpness settings on a ten-point scale, allowing users to fine-tune the display to their preferences. In UFO tests, the OLED matrix showcases its strengths by eliminating any blurring. The ultra-fast pixel response ensures dynamic movements are faithfully reproduced.

Similar results can be seen in other sizes of this model with a WOLED matrix, which also offer outstanding image fluidity. Organic technology, in this case, is considered among the best on the market. The S90D image, regardless of the matrix type, is exceptionally sharp and detailed, making this television perfect for dynamic scenes, whether for gaming or sports broadcasts. Additionally, its refresh rate and sharpness capabilities guarantee that every movement is smooth and natural, satisfying even the most discerning users.

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 S90D television is an excellent solution for gamers, offering a range of advanced features that elevate gaming quality to a new level. Equipped with HDMI 2.1 standard, the model supports modern technologies such as VRR (Variable Refresh Rate) and ALLM (Auto Low Latency Mode). Thanks to these solutions, the image is incredibly smooth, and the response to commands is instantaneous, which is crucial in dynamic titles. Additionally, the S90D supports HLG (Hybrid Log-Gamma) as well as G-Sync and FreeSync image synchronisation. This enables a perfect connection with Xbox, PlayStation, or PC, eliminating issues with tearing and stuttering. The built-in operating system offers the Xbox Game Pass app, providing access to a vast library of games directly from the television. This solution makes gaming even more convenient and accessible. The Game Bar feature provides quick access to essential information, such as current settings, performance statistics, and the ability to adjust image options. This allows for on-the-fly display parameter modification, which is extremely useful during intense gameplay. Despite lacking support for Dolby Vision, the S90D still offers excellent HDR image quality, allowing for full utilization of the potential of games and movies. As a result, the S90D represents a unique combination of modern technologies, outstanding image quality, and intuitive features, perfect for any gaming enthusiast.

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.