OLED is officially a mature TV technology.
For the last four years, LG's TVs with OLED panels -- that's organic light emitting diode screens -- have taken top honors for picture quality in CNET's reviews. Every year they beat the best LCD-based TVs, and every year I call the newest LG OLED the best TV I've ever tested.
That's the case once again. As of April 2018, the LG C8 is the best TV I've ever tested, beating the 2017 Sony and LG OLED TVs by a hair. And it's a thin hair: The C8's main advantages are really minor, including slightly better screen uniformity and ephemeral new video processing options.
Anybody who bought a 2017 OLED TV can rest assured that the newest version isn't significantly better (and has an uglier stand). For anybody who wants to save money by getting a 2017 OLED TV on closeout now, rather than waiting until this fall for the C8 to drop in price, consider this review a green light. (Note that Thanksgiving week has been the best time to buy LG's OLED TVs in recent years.)
The C8 is the cheapest this year with LG's new Alpha 9 processor, something that will be missing from the B8 when it appears this summer. But the B8 will be less expensive. And that processor isn't worth much extra money in terms of real-world performance, from what I've seen. In other words, the B8 is definitely worth waiting for if you want the best price on a 2018 OLED TV.
And for people who just want the best TV, regardless of price, it also pays to wait. Samsung's Q9 costs more than the C8, but promises a brighter image and the best quantum-dot, local dimming tech that LG's arch-rival can muster. It's the only 2018 LCD TV that I think may have a chance to equal an OLED. Meanwhile cheaper models such as the Vizio P-series Quantum could also make a play for videophiles who crave brightness -- or fear OLED burn-in.
It's early in the game, but the LG C8 is still my favorite to win the 2018 picture quality championship.
Sleek looks beyond the weak stand
I've loved LG's minimalist OLED designs in the past, but the 2018 C8 is more of a miss in my book. The included stand is really wide, almost the same width as the panel, and it scoops up to either side. I much preferred the cleaner look of the narrower, angular stand on the C7 from last year.
Of course you could always ditch the stand, wall-mount the TV and bask in its glorious minimalism. There's less than a half-inch of black frame around the picture itself to the top and sides. Then there's a bit more below, but no trace of silver, no "LG" or any other logo at all.
Seen in profile, the top portion is razor thin at just a quarter-inch deep. But it has the typical bulge at the bottom that juts out another 1.75 inches. That bulge houses the inputs, power supply, speakers and other depth-eating TV components. It's plastic, but the backside above it is sheathed in silvery metal.
New for 2018, LG updated the screensaver that appears when the TV isn't receiving a signal. Now it's an actual framed picture, including paintings and photographs of landscapes, and the frame itself changes too. My first thought is that LG wants to ape the panache of Samsung's The Frame in software form.
Smart TV: Decent but not innovative
LG's Web OS menu system feels nice and snappy but it's basically unchanged from last year. It still lacks the innovative extras and app-based setup of Samsung's 2018 Tizen system, and falls well short of the app coverage of Roku TV or Sony's Android TV. If you want more apps, your best bet is to get an external streamer, but it's worth mentioning that only one, the Apple TV 4K, can support Dolby Vision.
The remote is the same as the 2017 model's. I like using its motion control to whip around the screen, something that's particularly helpful when signing into apps or searching using an on-screen keyboard. The scroll wheel is also great for moving through apps, like those seemingly infinite thumbnail rows on Netflix and Amazon.
Both of those apps get dedicated launch buttons on the remote, by the way. But unlike Sony's 2018 remote there's no special logo-infused key for Google Assistant. LG's 2018 sets will soon include Assistant, which you can access by pressing the plain-Jane mic button, but it wasn't yet active when I reviewed the TV. I'll update this section when I get the chance to test it.
Features and connections
|HDR10, Dolby Vision
OLED's basic tech is closer to late, lamented plasma than to the LED LCD (QLED, quantum dot or otherwise) technology used in the vast majority of today's TVs. LCD relies on a backlight shining through a liquid crystal panel to create the picture, while each individual sub-pixel is responsible for creating illumination on OLED and plasma screens. That's why OLED and plasma are known as "emissive" and LED LCD are called "transmissive" displays, and a big reason why OLED's picture quality is so good.
LG's 2018 OLED TVs have the same light output and color gamut capabilities as 2017 models, so the biggest picture quality difference is that the 2018 TVs (aside from the B8, due later this year) get LG's new Alpha 9 processor. The company claims the chip improves noise reduction, sharpness, contrast and color (the latter with superior color mapping). LG also added black frame insertion to all of its 2018 OLED TVs, including the B8. See the picture quality section below for more details.
Unlike Samsung, LG TVs like the C8 support both major current types of HDR video: Dolby Vision and HDR10. The set also supports HLG HDR as well as Technicolor and Philips' HDR format. But you should think of them as future-proofing features as there's no content you can watch in those formats yet. A Technicolor-approved picture mode is also available.
New for 2018, LG's TVs are also compatible with HFR (high frame rate) video, although only through built-in streaming apps, not on external devices connected by HDMI. The presentation of higher frame rates in a handful of movies -- for example, The Hobbit and Billy Lynn's Long Halftime Walk -- is controversial. Many viewers simply don't like the effect, which can give films a similar look to the much-maligned soap opera effect. That said, it might become more widely accepted in sports and gaming content. Again there's no HFR content available yet, but LG says it might appear later in 2018.
In addition to its standard burn-in prevention measures, LG's added one called "Logo Luminance Adjustment." It's designed to automatically detect a static on-screen logo and, after two minutes, start decreasing its brightness over about a minute and a half, after which the logo should be 20 percent dimmer. CNET's initial tests of the feature found it does reduce logo brightness a bit, but we don't expect it to be a cure-all given the relatively mild percentage decrease.
The selection of connections is top-notch. Unlike many of Samsung's sets, this one actually has an analog video input for legacy (non-HDMI) devices, although it no longer supports analog component video.
- Four HDMI inputs with HDMI 2.0a, HDCP 2.2
- Three USB ports
- One composite video input
- Optical digital audio output
- One RF (antenna) input
- RS-232 port (minijack, for service only)
- Ethernet (LAN) port
With both HD and 4K HDR sources, in bright rooms and dark, the LG C8 delivered the best picture I've ever tested. It evinced perfect black levels and best-in-class contrast, as well as superb color accuracy. Off-angle was better than any LCD, and uniformity superior to any OLED we've tested at CNET -- including the 2017 models in this comparison.
Video processing is excellent but still falls short of some TVs' motion resolution. The impact of LG's Alpha 9 processor is minor, but LG added the ability to tweak some settings (such as HDR remastering), as well as including black frame insertion (which isn't worth the trade-offs in my view). Overall C8 is very slightly better than 2017 OLED TVs, but they all deserve a picture quality score of "10".
Click the image at the right to see the picture settings used in the review and to read more about how this TV's picture controls worked during calibration.
Dim lighting: This category was an unfair fight between the three OLED TVs and the three less-expensive LCDs. As usual OLED dominated in a demanding home-theater environment. The 2018 C8 didn't look any better overall than the 2017 OLED models, the Sony A1E and the LG E7.
Comparing the Thor: Ragnarok 1080p Blu-ray between the six TVs, the OLEDs showed their typically perfect black levels in the letterbox bars and correspondingly darker shadows, which improved contrast and impact over the LCDs. The dark scenes, such as Thor's initial confrontation with Surtur in the beginning or the lights against the dark screen at the beginning of Chapter 7, for example, exhibited the OLEDs' advantage well. Brighter scenes in Asgard levelled the playing field between the TVs more evenly later on.
The three OLED sets looked almost identical in most scenes, but I did notice slight differences in shadow detail. In Chapter 7 the shadowy machinery behind Thor looked a bit lighter on the E7 and the Sony compared to the C8. The C8 measured the best gamma of the three after calibration, coming closest to my BT1886 target, which might explain the difference. In any event the differences between the three were subtle.
Bright lighting: The C8 doesn't get any brighter than last year's OLED TVs. It actually measured slightly dimmer in SDR mode and slightly brighter in HDR, so I'll call it a wash. And as usual it can't compete with the light output of the LCD-based models in our lineup, including the TCL 6 series.
That said, the OLED sets are still bright enough for just about any viewing environment. Yes, they do get significantly dimmer than the LCDs when showing full-screen white -- think a hockey game, for example -- but even in those situations they're hardly dim.
Light output in nits
|10% window (SDR)
|Full screen (SDR)
|10% window (HDR)
All of the OLED sets preserved black levels and reduced reflections very well -- better than the TCL and Sony albeit worse than the Samsung, whose handling of reflections is among the best I've ever seen.
Color accuracy: Before my standard calibration, the Technicolor Expert and ISF Expert modes were already super-accurate, among the best I've seen, and afterward they were even better. As usual OLED's superior black levels also improved the perception of color saturation compared to the LCD displays.
Despite the C8's advantage in my measurements compared to the other OLED TVs, however, colors looked exceedingly similar and none of the three had a clear advantage. Frankly the LCDs, beyond the saturation difference, also looked basically as good.
Video processing: The C8 did well in this category, but I didn't see a massive difference I could chalk up to LG's new Alpha 9 processor.
With the Real Cinema setting turned on, the C8 passed my go-to 1080p/24 film cadence test from I Am Legend in both the "Off" and the "User" (zero for De-Judder and 10 for De-Blur) TruMotion position. I'd probably choose the latter since it also delivered the TV's maximum motion resolution (600 lines) and correct film cadence.
I definitely wouldn't choose the mode that introduces black frame insertion, new for 2018. Labeled Motion Pro, it can be toggled on and off in the TruMotion User menu. Turning it on improvedmotion resolution somewhat, perhaps to 700 lines while also making those lines sharper. But it also dims the image by about 40 percent, adds a subtle pulsing effect to 24-frame motion and introduces visible flicker to bright areas. The extra motion resolution isn't worth those trade-offs in my book.
The rest of the settings (with the exception of Off) introduced some form of smoothing, or soap-opera effect, and all maxed out at 600 lines of motion resolution. In comparison, the Samsung Q8 hit 1,200, which might make it more appealing for sticklers who can't stand blurring. To my eye, however, the LG remained plenty sharp in motion with all the actual program material (as opposed to test patterns) I watched.
The one advantage the Alpha 9 brings that I saw was in removal of the contouring artifacts in some material. The skies in The Martian 4K Blu-ray, for example, occasionally showed exceedingly faint bands of color (at 46:37 for example) on many TVs, including the C8 when its MPEG noise reduction is set to "Off." Turned on, however (in the Low or higher setting, or Auto), that banding essentially disappeared. I saw the same behavior on the Sony when I engaged its "smooth gradation" setting, and I prefer Sony's implementation since it doesn't force you to engage NR to combat banding. Thanks to Vincent Teoh at HDTV test for first reporting on LG's setting.
Input lag in Game mode with 1080p sources measured an excellent 21 milliseconds, the same as the E7 and superior to the Sony A1E. With 4K HDR it was a similarly impressive 29.97ms.
Off-angle viewing and uniformity: One big OLED advantage over LCD is its superb image when viewed from off-angle, in positions other than the sweet spot directly in front of the screen. The OLEDs maintained black level fidelity and color accuracy much better than any of the LED LCDs I've tested, all of which (including ones in this lineup) wash out in comparison.
Screen uniformity on the C8 was the best I've ever seen on an OLED TV, and better than the A1E or the E7, which both evinced vertical banding on dark, full-field patterns. Banding was still visible on the C8, in some patterns, but it was exceedingly faint. That said, I didn't notice any banding, or any difference between the three OLEDs' uniformity, with regular program material as opposed to test patterns, so I don't consider it a big advantage of the C8 (and, like all uniformity issues, can vary per sample).
The LCDs, for their part, showed much more noticeable uniformity issues than the OLEDs, for example, brightness variations across the screen.
HDR and 4K video:The C8 matched the HDR performance of the 2017 OLEDs in my lineup, but didn't significantly exceed them. Contrast was about the same -- not unexpected since light output was similar and so was OLED's perfect black -- and color was likewise tough to distinguish between the three, although I did see some subtle differences. All three outperformed the LCDs, including the brighter Sony and Samsung, and in fact the TCL was the best HDR performer among the LCDs in a dark room.
For my main HDR test I watched Altered Carbon from Netflix via a Roku Ultra in HDR10, compared side-by-side on all six comparison TVs. The show combines artistic shots with some of the best, most dramatic HDR I've seen, and provides a great test of the TVs' handling of highlights, shadows and everything in between.
The OLEDs consistently looked better than the LCDs, on the strength of their perfect black levels and overall contrast. Yes, the LCDs can technically get brighter. In episode 6 a blast of flashlight in the lower-right measured 355 nits on the C8 compared to 515 on the Samsung Q8. The OLED's bright areas still looked more impactful, however, because they were juxtaposed next to darker blacks.
Colors -- the lush green moss and plants, for example -- and the skin tones of the combatants in the forest in episode 7 also looked a bit more saturated and brilliant on the OLEDs. All three OLED TVs beat the Sony and TCL in terms of P3-DCI color gamut measurements, for what it's worth, and that factor plus the OLEDs' black level advantage could be the difference.
I expect the Samsung Q8 to match the gamut measurement of the OLEDs thanks to its quantum dot technology, and it will be interesting to compare their HDR color, but due to the color bug I mentioned before, I couldn't do so for this review. I'll revisit the comparison in the Q8 review once the bug is addressed.
According to measurements the C8's color was just as accurate if not more so than the other two OLED TVs, but if I had to choose between them I'd give the C8 the slight edge. In most scenes they looked very similar, but in a few the C8 looked more pleasing and punchy, with more vibrant colors and highlights. It was a very subtle, hair-splitting difference and wouldn't be visible outside a side-by-side comparison (and could easily be due to panel or calibration differences), which is why I still give them the same overall marks.
New for 2018, LG breaks out its Dynamic Tone Mapping setting, which is designed to mimic dynamic metadata with HDR10 and other static metadata sources by analyzing every scene and adjusting contrast according to LG's special sauce. It's on by default in Technicolor Expert and so all of the above observations and measurements were made with it engaged. Turning it off generally led to a duller image, so I left it on. Note that you can't turn it off on 2017 LGs such as the E7, but some people might appreciate having the toggle.
|Black luminance (0%)
|Peak white luminance (SDR)
|Avg. gamma (10-100%)
|Avg. grayscale error (10-100%)
|Dark gray error (30%)
|Bright gray error (80%)
|Avg. color checker error
|Avg. color error
|1080p/24 Cadence (IAL)
|Motion resolution (max)
|Motion resolution (dejudder off)
|Input lag (Game mode, 1080p)
|Peak white luminance (10% win)
|Gamut % UHDA/P3 (CIE 1976)
|Avg. color checker error
|Input lag (Game mode, 4K HDR)
Read next: How we test TVs