The LG UM6900 is a passable entry-level 4k TV with an IPS panel. Like most IPS panel TVs, it isn't well-suited for dark rooms, as its low contrast ratio and poor black uniformity result in blacks that look grayish. Motion blur is minimal thanks to its decent response time, but there's no black frame insertion feature to further improve motion clarity. Also, the backlight's 120Hz flicker causes noticeable duplication in motion, which can be distracting. Unfortunately, even though it has good reflection handling, it can't get very bright, so visibility can be an issue in bright rooms. Its low input lag provides a responsive gaming experience; however, it lacks support for any variable refresh rate technology to reduce screen tearing. Lastly, it uses a less accurate sub-pixel structure, which isn't ideal for use as a PC monitor.
Note that the 60" and 70" models likely use VA panels, and we expect them to have better contrast and black uniformity, but worse viewing angles.
The LG UM6900 is passable for most uses. It's best-suited for watching TV shows, sports, or playing games. Its wide viewing angles make it a good choice for a wide seating area; however, it doesn't get very bright, so it isn't suitable for bright rooms. Unfortunately, it isn't very good for watching movies in SDR or HDR, as it has a low contrast ratio, bad black uniformity, and no local dimming. It has a decent response time and outstanding low input lag, which would make it a great TV for use as a PC monitor, but the RGBW pixel structure isn't as accurate.
The LG UM6900 is sub-par for watching movies. It has a low contrast ratio that makes blacks look gray and there's visible clouding throughout the screen, which can be distracting. Furthermore, it doesn't have a local dimming feature. It can remove judder from 24p sources, but not when watching movies from a cable box.
The LG UM6900 is decent for watching TV shows. It has decent viewing angles, so you can walk around while watching without losing too much image quality. Reflection handling is good; however, this TV doesn't get very bright, making it difficult to see in bright rooms. It upscales lower resolution content from cable TV well, and you can safely leave it on the news all day without having to worry about permanent burn-in.
The LG UM6900 is a decent TV for watching sports. It has decent viewing angles, which is great for watching a big game with family and friends. It has a decent response time, but it doesn't have an optional black frame insertion feature to further improve motion clarity. Unfortunately, even though it has good reflection handling, it can't get very bright, so it isn't well-suited for a bright room. There's also some dirty screen effect, and the backlight's flicker causes visible image duplication.
The LG UM6900 is decent for playing video games. It has extremely low input lag and it has a decent response time that results in only a short blur trail behind fast-moving objects. Sadly, it doesn't support any variable refresh rate technology and its low contrast makes it less ideal for gaming in the dark.
The LG UM6900 is sub-par for watching HDR movies. Its IPS panel has a low contrast ratio and poor black uniformity, and it doesn't have a local dimming feature. Additionally, it can't get very bright in HDR and can't display a wide color gamut.
The LG UM6900 is okay for gaming in HDR. It has low input lag and decent response time; however, it can't display a wide color gamut and doesn't get very bright, so highlights don't pop the way they should. Also, it has a low contrast ratio that makes blacks look gray, it doesn't have a local dimming feature, and it doesn't support any variable refresh rate technology.
Although the LG UM6900 has a low input lag and it supports chroma 4:4:4, it uses the less accurate RGBW sub-pixel structure, which results in some visible artifacts when using the TV as a PC monitor.
The LG UM6900's design is very basic and feels a bit cheap. It looks very similar to the LG UM7300 but appears to be made of slightly cheaper materials. The stand doesn't support the TV very well as it wobbles a lot, and there's no cable management.
The feet are set almost as wide as the TV itself, so you'll need a large table if you don't plan on wall-mounting it. The feet don't support the TV very well, and there's a lot of wobble.
Footprint of the 49" model: 40.7" by 9.2".
The back of the TV is very plain. Unfortunately, there's no cable management at all.
The borders are a bit thicker than most higher-end models and they protrude from the screen, so they're a bit more noticeable when watching TV.
The LG UM6900 is a bit thicker than most higher-end models; however, it shouldn't stick out too much when wall-mounted unless you use the back-facing ports.
The build quality is mediocre and is almost identical to the LG UM7300. There's a lot of flex in the back panel, especially the area surrounding the inputs. The stand doesn't support the TV well, causing a fair amount of wobble.
The contrast ratio is sub-par, which is expected of most IPS TVs. This results in blacks that look gray, and is especially noticeable in a dark room.
Note that the 60" and 70" models likely use VA panels, and probably have better contrast.
This TV doesn't have a local dimming feature. The above video is provided for reference only.
This TV has a bad SDR peak brightness, so visibility can be an issue in bright rooms. The brightness doesn't vary much across different content and the slightly dimmer 2% window isn't noticeable.
We measured the SDR peak brightness after calibration, using the 'Expert (Dark Room)' Picture Mode and with Brightness set to max. Unfortunately, the other picture modes aren't noticeably brighter.
Poor HDR peak brightness. It isn't bright enough to make small highlights stand out in HDR content. On the upside, the brightness is fairly consistent, with only the 2% window being dimmer due to frame dimming.
We measured the HDR peak brightness before calibration, using the 'Cinema HDR' Picture Mode and with Brightness set to max.
If you don't mind losing image accuracy, you can reach a peak brightness of 383 cd/m² by using the 'Vivid' Picture Mode, with Brightness and Contrast set to max.
Gray uniformity is okay. The corners of the screen are visibly darker and there's also some dirty screen effect, which isn't great for watching sports.
Decent viewing angles. This is good if you have a wide seating area, or if you like to move around a bit with the TV on.
Note that the 60" and 70" models likely have VA panels, and probably have a worse viewing angle.
Bad black uniformity. There's noticeable clouding throughout the screen as well as backlight bleed at the top and bottom left corners, which can be distracting in dark scenes.
Note that the 60" and 70" models likely have VA panels, so they probably have better black uniformity.
Good reflection handling. Glare can still be an issue in a bright room, though, or if you have light sources opposite the TV.
Before calibration, the color accuracy is mediocre. While balance is off, gamma doesn't follow the target at all, and the color temperature is much warmer than our 6500K target, giving the overall image a slight reddish tint. Also, there are inaccuracies in most colors.
After calibration, the color accuracy is outstanding. White balance is nearly perfect and gamma follows the target for the most part, with only some over-brightening in very bright scenes. The few remaining inaccuracies aren't noticeable, but color temperature is still a tad on the cold side.
You can see our recommended settings here.
720p content, like most cable TV channels, looks great, with no obvious issues.
1080p content, like movies on Blu-ray, looks excellent. There are no obvious issues.
This TV uses a less accurate RGBW pixel structure. Learn more about RGBW.
This TV has an okay color gamut, but it can't display a wide color gamut. The EOTF doesn't follow the PQ curve properly, and almost all scenes are displayed brighter than they should be, including in 'Game' mode. If you find HDR too dim, the 'Vivid' Picture Mode is a bit brighter, as shown in this EOTF.
The LG UM6900 has a poor color volume. Colors aren't as bright as pure white, and it can't display dark, saturated colors very well due to the low contrast ratio.
Excellent gradient handling. There's some very slight banding, but this shouldn't be noticeable to most people. If banding bothers you, enabling Smooth Gradation can help, but it can also cause a loss of some fine details.
There are no signs of temporary image retention on the LG UM6900, even immediately after displaying our static test image for 10 minutes.
Although some IPS panels can suffer from temporary image retention, this doesn't appear to be permanent as the IPS panel in our long-term test appear immune.
Decent response time. There's some slight overshoot in some transitions, which can be noticeable in dark scenes. The flicker of the backlight causes noticeable duplications in motion, which can be seen in the above photo.
Update 06/17/2020: There was a minor mistake in our BFI scoring. It's been corrected, and the score has increased a bit.
There's no black frame insertion feature on this TV. The backlight always flickers at 120Hz, though, which helps improve motion clarity compared to a TV with no flicker.
This TV has an optional motion interpolation feature, which can be used to increase the frame rate of low frame rate content up to 60 frames per second. This can help improve the appearance of motion, but also introduces something known as the "Soap Opera Effect", which may bother some people. If you want to use motion interpolation, set TruMotion to 'User' and adjust the De-Judder slider to '10'.
The relatively slow response time of this TV results in less noticeable stutter. Some stutter can still be seen with 24p movies, though, especially in slow, panning shots.
This TV can remove judder from 24p sources and native apps, but not from 60p or 60i sources. To remove judder from 24p content, the Real Cinema setting must be enabled.
The LG UM6900 doesn't support any variable refresh rate technology.
This TV has outstanding low input lag, as long as it's in 'Game' mode. The input lag rises slightly when playing in HDR but shouldn't be noticeable for most people. There's an 'Auto Low Latency Mode' that activates 'Game' mode when it detects a game being launched from a compatible device, such as a PC or an Xbox One. To use this feature, make sure that Instant Game Response is enabled for the input in use.