What is the LG C6?
Connections & Control
The sideways-facing connections are comprised of three USB ports (two 2.0 and one 3.0) and three HDMI 2.0a inputs with support for Ultra HD 4K 50/60p, HDR and HDCP2.2. We confirmed that all the HDMI inputs were capable of accepting Ultra HD 4K 50/60p, HDR and HDCP2.2 using our Murideo Fresco Six-G test pattern generator. The second HDMI input supports ARC (Audio Return Channel) and there is also a 3.5mm analogue out/headphone jack facing sideways, along with a CI (Common Interface) slot.
Features & Specs
LG OLED55C6 Recommended Settings
Picture Settings - Out-of-the-Box
They also conveniently turn off most of the special features and select the correct Colour Temperature of Warm2. LG have recently added a Warm3 setting but this has too much red in the greyscale, so Warm2 remains closest to D65. As a result all you need to do is set the OLED Light, Contrast, Brightness and Gamma controls to suit your particular environment. You can set TruMotion depending on your personal preference but we would always recommend turning it off for film-based content and don't forget to turn the Horizontal and Vertical Sharpness controls down to zero and the Edge Enhancer off.
Picture Settings - Calibrated
Picture Settings - High Dynamic Range
So we have introduced new tests to see how a TV performs in terms of mapping the PQ EOTF for HDR, which can be mastered at up to 10,000nits, and tracking the Rec.2020 colour space within the confines of the TV's native colour gamut. The C6 supports both HDR 10 and Dolby Vision but for these tests we're using HDR 10 as the basis for our measurements. At some point Spectracal will add a 'golden reference' file for the LG OLEDs to CalMAN 5 which will allow us to calibrate them for Dolby Vision but in the meantime we're using test patterns produced by our Murideo Fresco Six-G and measured by our Klein K-10A.
When the C6 detects an HDR signal it automatically goes into the relevant and sensibly-titled HDR mode, which for an HDR 10 source is called HDR and for Dolby Vision is called Dolby Vision. A notice appears in the top right hand corner of the screen, identifying which type of HDR content has been detected. Regardless of which type of HDR it is, you rather unnecessarily have a number of choices when it comes to the HDR or Dolby Vision Picture Modes.
For HDR there is a choice of Vivid, Bright and Standard and we would always recommend using the latter; whilst for Dolby Vision the choice is Vivid, Movie Bright and Movie Dark and in this case Dolby themselves only recommend using Movie Dark. The majority of the controls default to their correct settings for HDR/Dolby Vision but we would recommend turning down any Sharpness controls, turning off the Edge Enhancement and TruMotion features and selecting the Wide Colour Gamut.
We measured black at 0.000nits and peak brightness at 560nits on a 10% window, which means the C6 does indeed meet the minimum criteria for Ultra HD Premium certification. However using a full-field peak white test pattern the C6 only measured 110nits, thanks to the ABL (Automatic Brightness Limiter). Despite only reaching a peak brightness of 560nits the C6 is still supposed to map content mastered at a higher peak brightness to the native capabilities of the display without clipping. Unfortunately when sending a 10,000nits HDR test pattern, the C6 was clipping above 600nits and this was also apparent when watching Ultra HD Blu-rays with HDR. We will discuss this in greater detail in the Picture Quality section.
Black Levels and Contrast Ratios
As you would expect from an OLED TV the C6 delivered absolute blacks in our tests with 0IRE measuring at 0.000nits, it was also able to easily hit our standard dynamic range target of 120nits. That equates to an on/off contrast ratio of infinity because we're dividing 120 by zero, so the ANSI contrast ratio is probably a more useful indicator and that was a superb 93,125:1. We naturally expected impressive contrast ratios numbers from the C6 but LG were at pains to stress that they have also improved the amount of detail or gradation just above black, which had been an issue with previous generations of OLED TVs.
When we talk about gradation, we're referring to the amount of detail visible as an image transitions from black into very very dark parts off the image that exist just above it. To improve this performance LG have built a slight dip into the gamma curve just above black that reveals more detail but you will also need to move the Brightness control up a couple of notches to avoid additional crush. We did see some slight noise and blockiness in areas just above black on occasion but overall we found that LG had indeed improved the near black performance, even if it wasn't as good as Panasonic's results in this area with their CZ952.
Screen Uniformity, Viewing Angles and Image Retention
Along with black crush another issue that has plagued earlier generations of OLED TVs has been banding in dark images just above black. Whilst this has certainly been improved, it was still apparent if we went looking for it with test patterns. However we were never aware of it when watching actual content. The other major issue with previous generations of OLED has been the vignetting or dark edges that tended to manifest when the TV was showing images with dark scenes just above black. We're pleased to report that LG have eliminated this problem and we couldn't see any issues with vignetting on the C6, even when we went looking for it.
Our review sample had no issues with screen uniformity, yellow tint or dead pixels; nor was there any of the banding, lines on the screen or other issues that have been reported by some other LG OLED owners. Aside from the issues that we mentioned in the previous paragraph, the panel in the C6 was free of any uniformity, discolouration or other issues and just delivered a great looking image. As we would expect from an OLED, the off-axis performance was also excellent and we could watch the screen from extreme angles and not suffer from a drop off in contrast or colour accuracy, nor was there any of the haloing you get from local dimming.
OLED is a self-emitting technology which is similar in that sense to plasma and, just like plasma, it could theoretically suffer from image retention and even screen burn. We have seen screen burn on OLED panels in the past but in previous testing we have never had an issues with either image retention or screen burn. LG have gone to great lengths to ensure this doesn't happen and safety features include dimming the screen if a static image is left up and washing the panel whilst in standby. We didn't have any issues with image retention on standard dynamic range content but when using HDR test patterns we did occasionally see image retention, although it quickly went away. So we would recommend being careful and avoid leaving static images up for too long.
As with all the other OLED TVs that we have reviewed to date, the C6 uses the 'sample-and-hold' approach, which means the panel displays and holds a static frame until the next one is refreshed. As a result the LG was delivering around 300 lines of resolution with TruMotion turned off. This could immediately be improved by selecting any of the TruMotion options (Smooth, Clear and User) but that will make film-based content look unnaturally smooth and we could see artefacts in some of our test material. Whilst we would always encourage you to experiment with TruMotion when watching sports content, we would usually recommend leaving it off for film-based content. Unlike with last year's LG OLED TVs we didn't experience any issues with judder, although if you do feel that there is noticeable judder, the de-judder control in the User TruMotion setting could help but you need to be careful because if you set it too high then film-based content will look too smooth.
Standard and High Definition
The C6 has excellent video processing that was able to take standard definition content and effectively deinterlace and scale it to match the native resolution of the panel. The resulting images were, at times, quite watchable and free of unwanted artefacts; although we often find standard definition broadcasts hard to watch, not through any fault of the TV but just because of the compression involved. When we watched a better standard definition source like DVD, the image was improved and when we moved on to high definition TV broadcasts the C6 was really able to show the kind of performance of which it is capable.
High definition forms the majority of our TV viewing these days and the better channels could look absolutely stunning, with the usual wildlife documentaries producing some of the best images. The combination of accurate colours, deep blacks and an impressive dynamic range all helped to deliver fantastic picture quality. The wider viewing angles, great motion handling and excellent screen uniformity also played their part and when we moved to Blu-ray, the image quality stepped up a gear. Regular test discs like Gravity and new ones like Zootopia looked fantastic and the overall performance of the C6 with high definition content was superb.
When we reviewed the LG EF950 OLED TV last year, we were rather disappointed by the 3D performance. The image suffered from the kind of crosstalk we were not expecting from a passive 3D display, although it might have been specific to our review sample – perhaps due to a slightly misaligned polarised filter. Thankfully the 3D performance on the C6 was absolutely stunning and amongst the best we have ever seen. The use of a passive polarised filter allowed a Full HD image to be delivered to each eye, with absolutely no crosstalk visible. We used the various 3D torture tests on the Spears & Munsil Blu-ray and the C6 passed with flying colours.
The new panel could deliver brighter images to combat the dimming nature of glasses, whilst the the black levels, colour accuracy and motion handling were excellent. The resulting 3D images were free of any distracting artefacts or flicker but had brightness and depth with a lovely sense of layering to the picture. We watched Zootopia again and the results were stunning, whilst regular test discs like Hugo, Gravity and Avatar looked stunning. Its rather ironic that just as 3D's popularity wanes and manufacturers begin to phase it out, we're seeing one of the best 3D performances we've experienced.
This is the name LG have given to their faux-HDR mode, which is similar in many ways to Samsung's new HDR+ feature. HDR Effect takes the original standard dynamic range signal and enhances it to create an experience that is intended to mimic HDR. It does this by mapping the Rec.709 colour gamut to the TV's native colour gamut and manipulating the gamma curve to brighten highlights and darken the shadows, resulting in a more contrasty image. The HDR Effect Picture Mode offers three different settings – Low, Medium and High – although we couldn't really see a noticeable difference as we cycled through the three options.
You can also change various picture settings, allowing you to customise the experience based on your personal preference. HDR Effect can't add what isn't there, so although an image may appear to have brighter highlights, the detail in those highlights will be the same as it was in the original source content. It also deviates from the industry standards, resulting in images that can appear over-saturated and highlights can appear blown-out. As a feature we preferred Samsung's more sophisticated HDR+ and in the case of the C6 we found the calibrated image was always preferable to the HDR Effect, even if you weren't an image purist.
We were very interested to see exactly how the C6 performed with HDR 10 content because up until now we have only tested LED LCD TVs. The decision by the Ultra HD Alliance to create two criteria, one for LED LCD and one for OLED raised the question of whether this was a legitimate distinction or one based on commerce. Whilst one one couldn't deny that the superior black performance of OLED gives its images a better foundation from which to create the dynamic range, does the limited brightness of the technology rob HDR content of its overall impact? As we mentioned earlier, when the C6 detects an HDR 10 signal it defaults to the HDR Picture Mode and we used HDR Standard. This mode defaults to the OLED Light and Contrast controls of 100 but you have the option to change them, as well as many of the other settings, if you so wish.
As we had already discovered when testing the C6 with HDR 10 test patterns, the OLED was clipping the specular highlights in certain scenes and changing the settings on the TV made no difference. This was particularly obvious in the arrival at Neverland scene in Pan, where the sun setting behind a mountain was just a blown-out patch of colour rather than a clearly defined circle. We often found that even if the highlights weren't clipped, they just didn't have as much impact as the same scenes viewed on an LED LCD TV. We happened to have the Samsung KS9500 at the same time as the C6 and in the scene from Pan that we just described, the sun was clearly defined on the KS9500. However, where the C6 does have an advantage is in terms of the precision with which it can handle specular highlights because the self-emitting OLED technology can accurately deliver them at a pixel level.
Where the C6 was also strong was at the other end of the scale with deep blacks and plenty of detail in the darker parts of the image. We found that our favourite darker scenes from Sicario and Mad Max: Fury Road looked particularly good on the C6. However these black levels also applied to standard dynamic range content, so whilst there is more detail in the HDR content, the difference isn't as big a revelation as it is with the brighter LED LCD panels. The other advantage of HDR is a wider colour gamut and here, as with Samsung's TVs, the colour accuracy of the C6 is skewed by the fact that it tracks DCI-P3 rather than Rec.2020. As a result a disc like The Revenant appeared more natural and realistic on both the Panasonic DX902 and the Sony XD94; although even more stylised films like Mad Max: Fury Road also looked more accurate on the Panasonic and Sony displays.
In many respects the C6 is a victim of its own success because the images with standard dynamic range content looked so good, that when watching HDR content it didn't appear as much of a step-up as it did with an LED LCD TV. In addition, whilst deep blacks are important, the ability to deliver the full 1,000nits of specular highlights also adds to the impact of the HDR image and the C6 struggled in this area. Ultimately, although we enjoyed watching HDR 10 content on the C6, we weren't as wowed as we were when watching the same content on TVs like the KS9500 or XD94.
At present, LG are the only manufacturer in the UK to offer TVs that support Dolby Vision. What is Dolby Vision? Well it is Dolby's proprietary version of HDR and although it shares some of its specifications with HDR 10, it is an end-to-end ecosystem. As with HDR 10, Dolby Vision can support a maximum peak brightness of up to10,000nits and the Rec.2020 colour space but it also has a maximum video depth of 12-bits as opposed to 10-bit with HDR 10. Dolby Vision uses dynamic metadata on a scene-by-scene basis, rather than the static metadata currently used by HDR 10. Perhaps most importantly Dolby Vision is a closed system, which means that Dolby control every aspect, from the mastering of the content to the final display. This means that the Dolby Vision content will contain metadata that identifies how it was mastered and the exact monitor used to master it and then Dolby's Intelligent Display Mapping Engine will ensure that the content is precisely mapped to the maximum capabilities of the display.
Although Dolby Vision is a great format, it is currently only supported by a few display brands because most manufacturers would rather use the open source HDR 10 than rely solely on Dolby for their HDR solution. Dolby Vision is delivered via the TV's SoC (System-on-Chip), which is why it can't be added to a non-Dolby Vision TV or upgraded. There is also limited Dolby Vision content available and at present the only source in the UK is Netflix. However Dolby Vision certainly shows promise and it is one of the big selling points of the C6. When the OLED detects Dolby Vision it defaults to one of three Dolby Vision Modes, although Movie Dark is the only one you should actually use. Interestingly unlike the HDR Modes, the OLED Light defaults to 50, rather than 100; although changing it didn't seem to make much difference and the majority of settings were greyed out. Although it isn't available yet, eventually the C6 will have a 'golden reference' file in CalMAN, so that it can be calibrated to ensure that it is perfectly setup
So how does it look? Well thanks to Dolby, we had a few scenes from the film Pan encoded in Dolby Vision, so we were able to compare them to the same scenes on the Ultra HD Blu-ray of the film which uses HDR 10. The Dolby Vision content looked wonderful on the C6 with deep blacks, plenty of shadow detail and well defined highlights, whilst the colours looked saturated but natural. On the C6 Dolby Vision was definitely superior to the same scenes on the Ultra HD Blu-ray because in HDR 10 the C6 was clipping highlights and skewing the colour gamut. However those same scenes looked almost as good on the KS9500, which also delivered deep blacks, plenty of shadow detail and well defined highlights. The one area where Dolby Vision did look better was in terms of colour accuracy but, like the C6 with HDR 10 content, the KS9500 was tracking DCI-P3 rather than Rec.2020.
We can't help but wonder if the reason LG has adopted Dolby Vision on their TVs is because the end-to-end solution and dynamic metadata are more suited to the inherent limitations of the OLED technology, resulting in a better HDR experience than with HDR 10. If that's the case then LG really need there to be more Dolby Vision content valuable because when it comes to HDR 10, the higher-end LED LCD TVs definitely have the edge.
Despite this the C6 has 40W of amplification built in and so can go quite loud without becoming harsh or brittle. We generally find that the Music option in the sound settings tends to provide the most balanced audio and so it was for the C6. Whilst this TV is never going to be able to deliver a room-shaking and immersive surround experience with modern blockbusters, it can certainly handle the majority of your regular content watching. However for the best sound experience, we would recommend that you seriously consider buying an outboard audio solution so that you can get the most from your new OLED TV.
LG OLED55C6 Video Review
Input Lag & Energy Consumption
The input lag reminded us of the strange measurements we were getting with the Sony XD93, where the reading on the C6 would gradually increase from 34ms to 42ms before cycling back to 34ms and repeating. We're not entirely sure why it was doing this but regardless of this recycling number an input lag of between 34 and 42ms shouldn't be an issue for the majority of gamers.
In terms of the C6’s energy consumption it proved to be fairly efficient. Using a a full window 50% white pattern we measured the out-of-the-box Eco Picture Mode at 130W and our calibrated ISF Expert (Dark Room) mode at 92W. Naturally once we moved on to 3D and HDR the level of energy consumption increased, with the LG drawing 125W in the 3D mode and 158W in the HDR mode.
How future-proof is this TV?
|4K Ultra HD Resolution|
|Colour Space (percentage of Rec.2020 - 100% best)||71%|
|HDMI 2.0a Inputs|
|HDCP 2.2 Support|
|4K Streaming Services|
|Smart TV Platform|
|Picture Accuracy Out-of-the-Box (score out of 10)||9|
|What do these mean?|
- Superb blacks and contrast ratio
- Marvellous dynamic range
- Great greyscale and colour accuracy
- Excellent video processing
- Wide viewing angles
- Supports Dolby Vision
- Impressive passive 3D
- WebOS remains effective
- Minor banding just above black
- Slight crush in shadow detail
- Clipping with HDR 10 material
- Rec.2020 tracking could be better
- Side inputs too close to edge
LG C6 (OLED55C6V) UHD 4K TV Review
Should I buy one?
As the first OLED TV that we have reviewed this year, the LG 55C6 has been largely impressive, retaining a number of key features, producing a great image and delivering on many of LG's promises for this latest generation. It might not have the stunning looks, superb construction or the built-in soundbar of the more expensive E6 and G6 but it remains an attractively designed and well made TV that will grace any modern living room. The sound quality was reasonable but the chances are you'll be using an outboard audio solution anyway, so why pay for the built-in soundbar? Assuming you don't mind a curved screen, you'll be getting the same picture performance for less money.
In terms of features the C6 has the lot, with an Ultra HD 4K 10-bit panel, a wider colour space and support for High Dynamic Range – both HDR 10 and Dolby Vision. The C6 is also certified as Ultra HD Premium by the UHD Alliance and includes a number of excellent Picture Modes, as well as a faux-HDR feature. There are three HDMI 2.0a inputs with support for Ultra HD 4K 50/60p, HDR and HDCP2.2, along with extensive calibration controls and a well designed menu system. The C6 comes with a Magic Remote and the latest version of WebOS, with support for all the main video streaming services. There's also support for passive 3D and the C6 comes with two pairs of glasses included.
The C6 delivered accurate out-of-the-box greyscale and colour gamut measurements and, thanks to the picture controls, it could produce a reference performance after calibration. The image quality with standard dynamic range content was superb, as we would expect from an OLED, with deep blacks and natural-looking colours. The viewing angles are very wide and the screen uniformity was good, whilst LG have succeeded in eliminating the dark edges that afflicted previous generations. There is still some minor banding just above black and the C6 could occasionally crush shadow detail in the darkest scenes but overall it produced a great-looking image with both standard and high definition content.
It's a shame that 3D is losing popularity and being phased out by most TV manufacturers because the C6 delivered a fantastic performance in the third dimension. The Full HD images delivered to each eye were bright and crosstalk-free, with deep blacks, natural colours and good motion handling. Whilst 3D is waning, HDR is fast becoming the hot new feature and the C6 supports both HDR 10 and Dolby Vision. However we did find that with HDR 10 the C6 clipped certain content and didn't track Rec.2020 correctly, so the performance wasn't as good as we have seen on other HDR displays. The performance was better with Dolby Vision but content is limited at the moment with Netflix currently being the main source in the UK.
Whilst the C6 could still produce a decent HDR image with far greater precision thanks to the general image benefits of OLED, it did sometimes lack the impact that is possible with some of the better LED LCD displays. There are also a number of other issues related to driving the panel harder with HDR content, such as image retention and life span, although in the case of the latter we'll have to wait and see. The energy consumption was very good, especially with standard dynamic range content and the input lag measured between 34 and 42ms, which should be low enough for most gamers. Our only other complaint would be that the side-facing HDMI inputs are too close to the edge of the screen but otherwise the C6 is a great OLED TV.
In fact when you consider all that you're getting for the £2,999 asking price, the LG OLED55C6 is a bit of a bargain and when you also take into account the great overall performance with high definition content in particular, as well as 3D, it's hard to see the downsides. So as long as you don't have an issue with curved screens, the C6 is definitely worth a Best Buy badge.
What are my alternatives?
Well if it's an OLED TV that you're after then currently you have a choice of the three other models that LG offer. If 3D isn't important to you and you'd rather have a flat screen then the B6 is the obvious alternative. Aside from the lack of 3D and the flat screen, the B6 is virtually identical to the C6, although the former does have four rather than three HDMI inputs. You can buy the B6 in the same 55- and 65-inch screen sizes and for the same £2,999 and £4,299 price tags. If you want a flat screen but you also want 3D, then you're looking at the E6 with its superior build quality, 'Picture on Glass' design and built-in soundbar. LG claim that the overall performance of the E6 might also be slightly better due to a different SoC (System-on-Chip) used but there is a £500 premium for the 55-inch model and a £700 premium for the 65-inch version. There's also the flagship G6 but it's essentially the same as the E6, is only available in a 65-inch screen size and will set you back a hefty £5,999.
If you're happy to consider an LED LCD alternative, then there's a decent selection of great performing TVs available this year. Panasonic were first out of the gates with their excellent DX902, you can get this flat model in either a 58 or 65 inch screen size and at competitive prices. The DX902 uses a full array backlight with local dimming, 512 zones and the most accurate colours on any TV currently available. If you prefer there is also the excellent Samsung KS9500 but you will have to move up to a larger 65 inch screen size. The curved KS9500 is slightly more expensive than the DX902 but also uses a full array backlight, with local dimming and offers a great HDR performance. If you're prepared to look at edge-lit LED LCD models then there have been some impressive models released this year including Samsung's curved KS9000 and Sony's flat XD93, both of which offer a full suite of features at various screen sizes and competitive prices.
Contrast/Dynamic Range/Black Level
3D Picture Quality
Picture Quality Out-Of-The-Box
Picture Quality Calibrated
Ease Of Use
Value for Money
Our Review Ethos
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