LG OLED C4 vs LG OLED C6 (WOLED)

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 HDR effect on the LG C6 is really very good. LG Display's new WOLED panel primarily brought a significant increase in brightness. In our unit we measured around 1,500 nits and, importantly, the TV can show similar values in many normal movie scenes. That gives HDR the proper impact. Bright highlights, lamps, or sunlight can be really strong, and most HDR movies simply look very impressive. Of course it's still an OLED, so brightness drops in scenes with a lot of white. The fifth scene of The Meg illustrates this well, where the C6 reached about 600-700 nits. That's still a very good result, but it also shows the new panel hasn't removed all the limitations typical of OLEDs.

Colors

When it comes to color, there is also little to complain about. The C6 covers about 99% of the DCI-P3 gamut and roughly 75% of BT.2020. In practice the colors are very saturated and, importantly, stable regardless of the scene. That's worth emphasizing, because not every TV behaves the same in this respect. In some RGB Mini LED models color saturation can depend more strongly on image brightness. Today a wider color gamut is mainly offered by QD-OLED TVs and new SQD models with a new generation of quantum dots. However, the C6 still performs very strongly here and is able to generate appropriately saturated colors in most movie scenes.

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.

Right out of the box the LG C6 is pretty well set up, especially if you choose Filmmaker mode. In SDR material the white balance is decent, although as brightness increases it starts to lack a bit of red. The picture becomes a little cooler as a result, but it’s not such a big difference that it stands out during normal viewing. More happens in the brightness response itself. Gamma is a bit low and instead of holding at 2.4 it sits closer to 2.1–2.2 over much of the range. In practice the C6 slightly brightens midtones. Shadows are therefore more readable, but the image loses some depth compared with how it should look in a dark room. In HDR the situation is a bit more interesting. The start of the grayscale looks very good, but from about 20–30% brightness the white balance starts to drift more and more. As brightness rises there’s more red and a noticeable lack of blue. In the brightest highlights the difference is already significant and also affects reproduction of some colors. The EOTF curve itself is handled fairly well over most of the range. The C6 only has a tendency to slightly brighten the image, which we also saw during our film comparisons. The largest deviation appears around the brightest highlights, where the TV begins to adapt the signal to the panel’s capabilities. So the out-of-the-box Filmmaker mode in HDR isn’t perfect, but overall it performs well. The biggest room for improvement is the white balance, especially at high brightness.

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.

LG TVs have been very receptive to calibration for years, and the C6 is no exception. After adjustment the white balance was set almost perfectly, and most color errors dropped to values below 3, often even around 2. In practice this means very accurate color reproduction in both SDR and HDR. An interesting detail appeared only with the HDR brightness characteristic. On a classic EOTF chart everything looks nearly ideal, and at first glance it would be hard to find fault. Only when we measured the TV’s behavior using filters based on actual movie scenes did it become clear that the C6 has a slight tendency to artificially boost image brightness.

It’s not a huge difference and many people may even see it as a positive, because HDR looks a bit more impressive this way. From the standpoint of fidelity to the source material this isn’t ideal — some scenes are simply a touch brighter than the filmmaker intended. Interestingly, this is somewhat unusual for LG. In previous generations, the brand’s TVs typically stuck very closely to the reference tone curve after calibration. With the C6 we’re still very close to the standard, but that subtle boost in brightness is indeed noticeable in films and series.

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 LG C6 has taken a really big step forward here. The TV uses the same processor found in the flagship G6, and in terms of image processing the two models are very similar. That’s a big plus, because in this area LG’s processor this year performs excellently. The "Smooth Gradation" feature works especially well. With heavily compressed material it can effectively hide ugly tonal transitions and artifacts that often appear, for example, in lower-quality streaming. It’s best to leave it set to "Low." Then the improvement is clear, and the TV doesn’t yet start blurring fine details. Higher levels smooth the image more, but can already remove some of the natural texture of objects on the screen. The upscaling itself also performs very well. Lower-resolution content is sharpened properly, edges look clean, and the processor quite effectively rebuilds fine details. In this regard the C6 is already very close to LG’s best TVs, and the differences compared with the G6 are small.

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 LG C6 features a panel with a maximum refresh rate of 165 Hz, which is great news especially for gamers using a powerful PC. For movies, sports, or consoles we'll of course use up to 120 Hz, but even then it's hard to fault the motion clarity. As you'd expect from an OLED, the panel's response time is almost instantaneous. Moving objects therefore don't leave the characteristic smears you still see on LCD TVs. This is particularly noticeable in sports and fast-paced games, where the picture remains very clean even during dynamic motion.

For movies and TV, LG also provides the TruMotion motion-smoothing system. In the user settings you'll find two separate sliders. De-Judder is mainly for low-frame-rate content, that is primarily 24 fps films and series. It can slightly reduce the characteristic judder, or be set higher if you want a much smoother image. De-Blur is useful for higher-frame-rate material, mainly sports broadcasts and 50/60 fps television.

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.

LG has focused heavily on gamers for years, and the C6 really lacks nothing important. The TV supports 4K at 120 Hz from consoles, and when connected to a PC it can run up to 165 Hz. It also offers VRR from 40 to 165 Hz, ALLM, and properly working HGiG. A big plus is Dolby Vision support for games, so the Xbox Series X can use that format without sacrificing game mode. The package is rounded out by a Game Bar that lets you quickly check key signal parameters and change settings without leaving the game. In terms of features, the C6 is one of those TVs that’s really hard to find fault with. Whether you play on PlayStation, Xbox, or PC, practically everything you could expect from a modern gaming TV is available here.