TCL QM851G  TV Review

The TCL QM851G has remarkable HDR brightness. Highlights really pop out during darker scenes, and it's bright enough that very bright specular highlights even stand out in well-lit scenes. Combined with its outstanding contrast, this TV provides a very impactful HDR viewing experience.

These measurements are after calibrating the HDR white point with the following settings:

• HDR Picture Mode: Movie
• Brightness: 100
• Contrast: 100
• Local Contrast: High
• Gamma: 2.2
• Micro Contrast: off
• Color Temperature: Warm -5
• Dynamic Tone Mapping: Off

The peak brightness in 'Vivid Mode' is even higher:

• Peak 2% Window: 4047 cd/m²
• Peak 10% Window: 3311 cd/m²
• Peak 25% Window: 3236 cd/m²
• Peak 50% Window: 1743 cd/m²
• Peak 100% Window: 924 cd/m²
• Sustained 2% Window: 2315 cd/m²
• Sustained 10% Window: 3204 cd/m²
• Sustained 25% Window: 3137 cd/m²
• Sustained 50% Window: 1738 cd/m²
• Sustained 100% Window: 923 cd/m²

The TV is even brighter with 'Dynamic Tone Mapping (DTM)' turned on. Results with DTM set to Detail Priority:

• Hallway Lights: 1665 cd/m²
• Yellow Skyscraper: 862 cd/m²
• Landscape Pool: 871 cd/m²

Results with DTM set to Balance:

• Hallway Lights: 1634 cd/m²
• Yellow Skyscraper: 929 cd/m²
• Landscape Pool: 884 cd/m²

Results with DTM set to Brightness Priority:

• Hallway Lights: 1576 cd/m²
• Yellow Skyscraper: 990 cd/m²
• Landscape Pool: 923 cd/m²

There's no visible difference in brightness when the TV is set to Game Mode. Highlights really pop out during darker moments in games, and it's bright enough that very bright specular highlights even stand out in well-lit games. Combined with its outstanding contrast, this TV provides a very impactful HDR gaming experience.

These measurements are after calibrating the HDR white point with the following settings:

• HDR Picture Mode: Game
• Game Master: On
• Brightness: 100
• Contrast: 100
• Local Contrast: High
• Gamma: 2.2
• Micro Contrast: off
• Color Temperature: Warm -5
• Dynamic Tone Mapping: Off

The TV is even brighter with 'Dynamic Tone Mapping (DTM)' turned on. Results with DTM set to Detail Priority:

• Hallway Lights: 1673 cd/m²
• Yellow Skyscraper: 857 cd/m²
• Landscape Pool: 848 cd/m²

Results with DTM set to Balance:

• Hallway Lights: 1658 cd/m²
• Yellow Skyscraper: 1026 cd/m²
• Landscape Pool: 882 cd/m²

Results with DTM set to Brightness Priority:

• Hallway Lights: 1583 cd/m²
• Yellow Skyscraper: 1104 cd/m²
• Landscape Pool: 902 cd/m²

The TCL QM851G has superb SDR brightness and easily overcomes glare in the brightest of rooms.

These measurements are after calibration with the following settings:

• Picture Mode: Movie
• Brightness: 100
• Contrast: 100
• Black Level: 50
• Dynamic Contrast: Off
• Black Stretch: Off
• Dynamic Brightness: Off
• Local Contrast: High
• Micro Contrast: Off
• Gamma: 2.2

The TCL QM851G has amazing contrast. Its native contrast is great, but with local dimming enabled, the TV displays very deep blacks that stay deep when brighter highlights are also on screen.

The TV's lighting zone precision is excellent, with only some minor blooming around bright objects and subtitles when displayed against a black background.

The TV has excellent lighting zone transitions, but it does struggle a bit with very fast-moving content. There's barely any haloing, but the leading edge of quick-moving objects is a bit dimmer.

There's no visible difference in dark scene performance when the TV is set to Game Mode.

The TCL QM851G has amazing black uniformity. With local dimming disabled, blacks are slightly cloudy and blueish. With local dimming enabled, blacks are deep and uniform across the screen, with only a bit of blooming around bright objects on a dark background.

The TV has good SDR color volume. It has impressive coverage of the commonly used DCI-P3 color space, although it can't quite fully display bright greens, yellows, and some reds. It has okay coverage of the wider BT.2020 color space; its color volume isn't quite good enough to fully display most colors, with the exception of some magentas.

The TV has outstanding color volume. It displays a wide range of colors at high luminance levels, and dark saturated colors are displayed well due to its outstanding contrast.

The TCL QM851G has good pre-calibration accuracy. Color accuracy is great, with only some inaccuracies with light yellows, light cyans, and whites. Its white balance is decent, but blues are overrepresented in darker shades of gray, and reds are overrepresented in all shades of gray, making the color temperature too warm. Gamma is pretty close to our target of 2.2, but all scenes are displayed brighter than intended.

The TV has fantastic SDR accuracy after calibration, and it's easy to calibrate. Gamma, white balance, and color temperature are now all essentially perfect. Color accuracy is outstanding, but there are still some very minor inaccuracies with darker blues.

You can see our full calibration settings.

The TV has sub-par pre-calibration accuracy in HDR. White balance is off, as there's too much red, and blue to a lesser extent, in brighter shades of gray. This makes the TV's color temperature slightly too warm. Color accuracy is inadequate, as almost every color is noticeably off the mark.

The TV's HDR accuracy is decent after calibration. White balance is much better, although there are still notable accuracy errors in darker and brighter grays. Color temperature is still too warm, but now color accuracy is vastly improved, with far fewer color mapping errors.

The TCL QM851G has poor PQ EOTF tracking. It favors brightness over accuracy, so content is displayed much brighter than intended. There's a sharp cutoff near its peak brightness with content mastered at 600 and 1000 nits, but no roll-off is necessary since the TV is bright enough to fully display content mastered at those brightness levels. With content mastered at 4000 nits, there's a slight roll-off to maintain some detail in very bright specular highlights.

We retested the TV's PQ EOTF tracking with firmware V8-T653T02-LF1V107 and confirmed there was no difference in the results. We also retested it on V113 during the 2.0 test bench update and confirmed that the PQ EOTF tracking is unchanged.

The EOTF tracking is much better on the TCL QM8K that replaces this TV, but it's not perfect, either.

The TCL QM851G has great low-quality content smoothing. It does an excellent job at smoothing out artifacts in low bitrate content, but there is some loss of detail.

The TV does a good job with upscaling low-resolution content like DVDs, standard definition cable channels, and lower-resolution streams. Details are clear enough, but finer details and small hard-coded text are hard to make out.

Sharpness processing was calibrated with no over-sharpening for low-resolution content, with the following settings:

• Sharpness: 20

The TV has very good HDR native gradient handling. There's some noticeable banding in grays, but all other colors have minimal banding or no banding at all.

This TV has low input lag, especially at 120Hz, when set to Game Mode with 'Game Master' turned on, which ensures a very responsive gaming experience with very little delay between your actions with your controller or mouse and the action on-screen. The input lag is 8ms when gaming in 1080p @ 240Hz.

Unfortunately, there's a reoccurring bug that prevents it from having the low input lag that it should while in Game Mode. To fix this, you have to power cycle the TV.

The TCL QM851G supports all common resolutions up to 4k @ 144Hz. HDMI 1 is the only port capable of 144Hz and 240Hz, while HDMI 2 can be used for gaming up to 120Hz. For 144Hz and 240Hz to work, you must enable 'High Frame Rate Mode.' Unfortunately, it doesn't support chroma 4:4:4 when set in Game Mode and needs to be set to PC to display chroma 4:4:4. Unlike last year's TCL QM850G, 1080p @ 240Hz with chroma 4:4:4 works without any issues as long as the TV is set to PC.

The TV supports all three types of variable refresh rate (VRR) technology to reduce screen tearing. Its VRR range caps out at 144Hz or 240Hz, depending on the resolution. Unfortunately, it uses different overdrive settings under and above 65Hz. If you're gaming and your frame rate hovers between 60fps and 70fps, there's noticeable overshooting.

There's an inconsistent bug that prevents VRR from working at all. Despite the TV saying that VRR is on, there's noticeable screen-tearing. Power cycling it fixes the issue, and VRR works correctly.

The TV's CAD at its maximum refresh rate of 144Hz is good. The TV does struggle more when going from a black screen to a dark gray or very bright gray shade, with some overshoot, leading to some motion blur and inverse ghosting.

The TV's CAD at 120Hz is okay. Still, it has severe overshoot when going from a completely black frame to a dark gray shade, leading to inverse ghosting.

The TV's CAD at 60Hz is decent. Much like at 120Hz and 144Hz, it overshoots when going from a completely black frame to a dark gray shade. This will again lead to obvious inverse ghosting in very dark content.

The TV is fully compatible with everything the PS5 offers, like 1440p @ 120Hz and 4k @ 120Hz, as well as HDMI Forum VRR. It also supports Auto Low Latency Mode, so you don't have to worry about manually switching to Game Mode to get the lowest input lag.

The TV is fully compatible with everything the Xbox Series X|S offers, including 1440p @ 120Hz, 4k @ 120Hz, HDMI Forum VRR, FreeSync Premium Pro, and Dolby Vision gaming. It also supports Auto Low Latency Mode, so you don't have to worry about manually switching to Game Mode to get the lowest input lag.

Due to the TV's quick response time, there's noticeable stutter when watching movies or TV shows.

The motion interpolation feature does a good job reducing stutter. The feature is very consistent, ensuring an even frame cadence, but you'll still see some stutter in slow panning shots.

The TV automatically removes judder from all sources when watching movies or shows that are in 24p, even if they're in a 60Hz signal, like from a cable box. The frame timing isn't quite perfect with 25p sources sent via a 60p source, like an older streaming device that can't match the content's frame rate.

There's very slight micro judder when watching 25p content sent at the native frame rate, but it's extremely minor.

The TCL QM851G has a great response time on average, but its performance varies significantly based on the actual scene transition, so there's still some noticeable black smearing, inverse ghosting, and motion blur when watching varied content.

Color transitions are smooth, with only very minor color artifacts. Edge transitions aren't, though, and there are significant edge artifacts.

The TCL QM851G uses pulse width modulation (PWM) to dim its backlight, which introduces flicker that can bother people who are sensitive to it. Fortunately, it flickers at an incredibly fast 30,000Hz in all picture modes and at all brightness levels, so it's not noticeable.

The TCL QM851G has an optional backlight strobing feature, commonly known as black frame insertion. This feature is meant to reduce persistence blur and improve the appearance of motion. It works well at both 60Hz and 120Hz, with only some very minor image duplication. Note that enabling this feature reduces the panel's overall brightness.

The TV has medicore direct reflection handling. You see your lamp, wall light, or window on the screen when watching content or playing video games in a bright room, and there's echoes of light to these reflections.

The TV has fantastic black levels in a well-lit room. Black levels barely go up in a bright room, so blacks stay deep and punchy.

The TV's amount of total reflected light is very good. It reduces the intensity of any ambient reflections quite well, but unfortunately, it does so with noticeable rainbow smearing.

The TV has great color saturation in a bright room. While there's some slight color degradation in well-lit contexts, moreso with high-luminance colors, it's minor and not very noticeable. Ultimately, colors stay crisp and punchy.

The TCL QM851G has a mediocre viewing angle, so it's not suitable for a wide seating arrangement. As you move off-center, there's significant gamma shifting, color shifting, and brightness loss, and colors look increasingly washed out as you move further away to the sides.

The TV has decent gray uniformity, but there's some dirty screen effect towards the center of the screen, and the corners are a bit darker than the center. On a very dark or near-black screen, its uniformity is excellent, but the corners of the screen are a bit lighter than the center.

The TV uses a BGR (Blue-Green-Red) subpixel layout instead of the traditional RGB layout. For video or gaming content, this doesn't cause any issues, but for PC monitor use, it can be a problem as it impacts the text clarity, although not everyone will notice this.

The TV uses quantum dots to achieve high color peaks with excellent separation between blues, greens, and reds. This gives the TV great color purity and allows it to display a very wide color gamut.

The TCL QM851G has HDMI 2.1 bandwidth on HDMI ports 1 and 2, but there are differences between them. HDMI 1 is the only port capable of 4k @ 144Hz and 1080p @ 240Hz, while HDMI 2 can be used for gaming up to 4k @ 120Hz. Fortunately, HDMI 4 is the eARC port, so you don't lose a high-bandwidth port when you plug in a soundbar. The TV supports all common HDR formats and has an ATSC 3.0 tuner, so you can watch over-the-air 4k content.

The TV supports eARC, which lets you pass high-quality, uncompressed audio to a compatible receiver or soundbar through an HDMI cable. It supports all major audio formats, so you don't have to worry about compatibility with external sources.

The TCL QM851G has a very similar design to last year's TCL QM850G. It has thin bezels on the sides and the top, with a slightly thicker bottom bezel. Unfortunately, the bezels have a reflective finish. If you have lights on in your room, you see distracting reflections on the bezels. There's also branding near the top corner on the right bezel that uses reflective writing that can also be distracting in a well-lit room. Additionally, there's a fairly large gap between the bezels and the screen.

The TV comes with a metal center-mounted stand that doesn't require a large table to place the TV on. The stand holds the TV well and can be adjusted into two different positions. The higher position (pictured above) lifts it about 3.5 inches above the table, so most soundbars fit underneath without blocking the screen. The lower position adds a bit of stability and only lifts the TV about 2.23 inches, which is great if you don't have a soundbar and want the screen as close to your table as possible.

Footprint of the 65-inch stand: 13.46" x 11.73".

The back is made of plastic and has a grid-like pattern that's very reminiscent of current Sony TVs. Most of the inputs are side-facing, but they're located in a recessed cutout that makes them a bit hard to access if you have the TV wall-mounted. There are two speakers located at the top, and the TV has a built-in ONKYO subwoofer located in the middle of the back of the TV. You can also funnel cables through the TV's stand to help with cable management.

The TCL QM851G has great build quality. It's mostly made of plastic, but it's sturdy and well-built overall. The TV has the usual flex near the VESA mounting points on the back and it wobbles a bit when pushed on, but neither of these cause any problems. There's no issues with quality control on our unit.

The TCL QM851G uses version 12 of the popular Google TV operating system. The interface is very smooth and easy to use.

Unfortunately, like almost all TVs on the market, the smart interface contains ads, and you can't disable them.

The TV comes with the same remote as last year's TCL QM850G. It has a motion-activated backlight, has buttons for popular streaming services, and you can use the built-in microphone to switch inputs, change apps, search within apps, and ask for the weather and time. Unfortunately, you can't change the settings on the TV using the voice controls.

There's a single button on the bottom center of the TV that can be used to switch inputs, adjust the volume, change channels, and power the TV on/off. There's also a small switch beside it that you can use to turn on/off the TV's built-in microphone.

• Setup guide
• Remote
• 2x AAA batteries
• Power cable

The TCL QM851G has a decent frequency response. Thanks to the built-in ONKYO subwoofer, it actually produces a bit of bass, but it's still not as good as the bass you get from a good soundbar. The sound profile is balanced enough that dialogue is easy to understand, but it does become more unbalanced at the TV's maximum volume.