TCL 6 series (2018 Roku TV) review: Still the best picture quality for the money, period

Picture quality


Click this image for picture settings and more.

Sarah Tew/CNET

LG's C8 OLED TV again sets the pace with a score of 10 in this subcategory, but the 6 series earns an 8 (Excellent), putting it in the company of LCD TVs that cost a lot more. 

In my side-by-side tests against the Samsung Q8 and Sony X900F, the TCL more than held its own, with deeper black levels and better contrast in many scenes than those more-expensive sets. It couldn't get quite as bright, but still has plenty of light output for bright rooms and high-dynamic-range TV shows and movies. Color accuracy and video processing were also a bit worse than those others, but by no means poor, and TCL improved uniformity significantly, which was an issue last year.

So no, the 6 series is by no means flawless, but even persnickety videophiles will find plenty to like -- especially at this price.

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: The TCL punched far above its weight in my dark-room comparison with the TVs calibrated to the same light output. Watching the incredible-looking 1080p Blu-ray The Greatest Showman, it kept pace with and in many ways exceeded the picture quality of the more expensive Samsung Q8 and Sony X900F, which are also equipped with full-array local dimming. It also looked better than 2017's Vizio M and the 55-inch TCL P series.

The key as usual was deep black levels, something the 6 series delivers very well. In the nighttime dance montage in Chapter 2, for example, its letterbox bars and the shadows between the buildings (9:22) looked and measured a darker shade of black than any of the other sets aside from the OLED. As a result the darker scenes looked just a bit more realistic and punchy on the TCL and a bit less realistic and washed out on the others. The differences were minimal to nonexistent in many scenes, and the contrast of the others was still excellent, but the 6 series had the slightest of advantages.

Shadow details were also excellent on the 6 series and better than what I saw on the Vizio or the TCL P series, which tended to crush the darkest areas slightly. The 6 series also controlled blooming, or stray illumination very well, although it had no clear advantage in this area with dim SDR (see below for HDR tests, however).

Bright lighting: The 6 series showed a big improvement in raw light output over last year, and outpaced all of the TVs in the lineup aside from the twice-as-expensive Samsung and Sony sets. Yes those two can get substantially brighter, which makes them a better choice for exceedingly bright rooms, but for the vast majority of rooms the TCL will be plenty bright enough.

Light output in nits

TV Mode (SDR) 10% window (SDR) Full screen (SDR) Mode (HDR) 10% window (HDR)
Samsung QN65Q8FN Dynamic 2348 638 Dynamic 2388
Sony XBR-65X900F Vivid 1183 696 Vivid 1203
TCL 65R617 Brighter/Vivid 653 480 Brighter/Dark HDR 824
Vizio P65-E1 Vivid 459 575 Vivid 498
TCL 55P607 Vivid/dimming off 438 431 Brighter/dark HDR 448
LG OLED65C8P Vivid 419 141 Cinema Home 792
LG OLED55C8P Vivid 418 140 Cinema Home 788
Vizio M65-E0 Vivid 288 339 Vivid 880

The 2017 Vizio M did get a bit brighter in HDR mode in its Vivid setting. That mode is highly inaccurate, however; in the Vizio's better Calibrated setting it fell short of the TCL (788 vs. 824 nits), and in HDR program material the TCL's highlights were better. I also appreciated that the TCL achieved its highest light output with local dimming set to the best (Local Contrast: High) setting. Last year you had to turn dimming off to get the TV at its brightest.

The TCL's matte screen didn't reduce reflections or preserve black level quite as well as the other sets in my lineup, but it was still very good.

Color accuracy: Prior to any adjustment my review sample showed a plus-red bias in its most accurate picture mode (Movie), which tended to make Caucasian skin tones look a bit too ruddy, for example. Even so, color was far from terrible before calibration, and most viewers would be hard-pressed to notice the reddish cast. After adjustment using TCL's superb system, however, color was as accurate as on any TV in my lineup.

Watching Showman, the TCL's color was excellent, with as much saturation and accuracy as any of the other LCD sets. Chapter 6 is packed with lots of bright and near-black color in the circus signs, the costumes of the performers and dramatic lighting, for example, and the 6 series delivered it all with a bit of extra richness compared with the other non-OLED sets. I chalk up the advantage to its superior black levels, which can improve apparent saturation.

Video processing: The TCL 6 series handled 1080p/24 content properly, preserving the cadence of film. New for 2018, there's a setting called Natural Cinema that's said to improve the look of film (24p) content, but in my standard test using the aircraft carrier flyover from I Am Legend, I couldn't see any difference whether the setting was turned on or off.

Two other new settings are also available now: Action Smoothing and LED Motion Clarity. The former introduces the soap opera effect in various strengths, but unlike such settings on most other TVs it doesn't improve motion resolution, which remained at the 300 lines typical of 60Hz TVs no matter how much Action Smoothing I applied. (As mentioned above I wasn't able to test the 75-inch size but I expect it to have a better result thanks to its 120Hz panel.)

LED Motion Clarity uses black frame insertion to boost motion resolution (to an impressive 1,200 lines) and combat blur, but comes with the usual trade-offs: a significantly dimmer image and visible flicker. I recommend all but the most blur-sensitive viewers keep it turned off.

The TCL has the lowest (best) input lag I've measured in a long time. With Game Mode engaged it was just 15.43 milliseconds with 1080p sources, and 17.5ms with 4K HDR sources. With it turned off, lag increased quite a bit to 56ms and 121ms, respectively.

Uniformity and off-angle: This category was a weakness for the 2017 P series, but not the 2018 6 series. With full-field test patterns it looked nearly as good as the others, with edges just slightly darker than the middle and no visible backlight structure as seen on the P. In tough program material, namely a hockey match, its dirty-screen effect was no worse than any of the other sets in my lineup, and definitely superior to its predecessor.

A mixed bag from off-angle, the 6 series preserved black-level fidelity better than the other LCDs aside from the P series -- it didn't wash out as badly -- but showed more color shift in bright areas. If I had to choose I'd prefer TCL's approach because it makes for better contrast from seats outside the sweet spot, at the expense of color accuracy.

HDR and 4K video: As usual for a good full-array local dimming TVs, the TCL's SDR strengths with SDR translated well into HDR too. Its image was brilliant and punchy, and while it fell short of the highlights achieved by the Sony and especially the Samsung, it showed a higher-contrast image in dark scenes. The only TV in my lineup that looked consistently better with all HDR images was the LG C8 OLED -- in other words the TCL held its own very well against the more expensive Q8 and X900F, and beat the 2017 M series once again.

For my first HDR test I slipped in the 4K Blu-ray of The Greatest Showman. The TCL's black-level advantages showed up best in darker scenes like the ballet recital (Chapter 7, 33:35). The TCL's letterbox bars and shadows behind the dancers appeared darker and truer than any TV aside from the OLED, while still preserving excellent shadow detail in the folds of the curtains. It's worth noting that the 2017 TCL P series came closest to the 6 series black level, but shadows in this scene and others looked less detailed and a bit muddy.

When the shot panned out to show the dancers, the Samsung (215 nits), Sony (139) and LG C8 (164) showed brighter, more impressive highlights in the central pink tutu (the TCL hit 97 nits), as well as in other highlights I measured. That brightness advantage did lend their images extra pop, in both mixed scenes like that and in brighter scenes, like the approach to the house at the beginning of the chapter. In my side-by-side comparisons I did prefer the look of those three more expensive TVs in brighter scenes over the TCL.

Blooming is often an issue in HDR with its extra brightness, but the TCL controlled it well, even in difficult sequences like the white-on-black credits at the end of Showman. None of the other non-OLED TVs kept the black area as free of stray illumination as the 6 series.

The TCL did appear less color-accurate than the three higher-end TVs, although it did beat the Sony and Samsung for richness and saturation in many scenes. Skin tones in the Showman appeared a bit redder in particular, although not as skewed as on the TCL P series or the Vizio M. According to my measurements it also fell shorter of their color gamuts, although in this film the disadvantage was tough to spot.

Playing Altered Carbon on Netflix, the TCL's less accurate color was apparent compared with the others. In Episode 1 as Kovacs (Joel Kinnaman) talks to the barkeep (45:05), for example, their skin tones looked a bit too reddish and oversaturated, and that slightly reddish case applied to the plush chairs and lighting in the room as well. The 65R617's color issues showed up in my measurements as well, where the color checker showed more overall errors than competitors. That said, color wasn't terrible, and as usual it would be a lot tougher to see the difference beyond a side-by-side comparison.

Geek box

Test result Score
Black luminance (0%) 0.0008 Good
Peak white luminance (SDR) 653 Good
Avg. gamma (10-100%) 2.39 Good
Avg. grayscale error (10-100%) 0.39 Good
Dark gray error (30%) 0.04 Good
Bright gray error (80%) 0.16 Good
Avg. color checker error 0.70 Good
Avg. color error 0.42 Good
Red error 0.43 Good
Green error 0.42 Good
Blue error 0.85 Good
Cyan error 0.37 Good
Magenta error 0.14 Good
Yellow error 0.30 Good
1080p/24 Cadence (IAL) Pass Good
Motion resolution (max) 1,200 Good
Motion resolution (dejudder off) 300 Poor
Input lag (Game mode) 15.43 Good


Black luminance (0%) 0.004 Good
Peak white luminance (10% win) 825 Average
Gamut % UHDA/P3 (CIE 1976) 94.63 Average
Avg. color checker error 3.42 Average
Input lag (Game mode, 4K HDR) 17.5 Good