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LG UF6400 TV Review

Tested using Methodology v1.0
Reviewed Dec 03, 2015 at 12:00 am
LG UF6400 Picture
Test Methodology v1.0
6.6
Mixed Usage
Value for price beaten by
: Not at the latest test bench
6.1
Movies
7.0
TV Shows
6.9
Sports
7.0
Video Games
5.9
HDR Movies
4.3
HDR Gaming
6.5
PC Monitor
Type LED
Resolution "4k"
Refresh Rate 60 Hz

The LG UF6400 LED TV is the second 4k TV we have seen from LG which uses the less accurate RGBW pixel structure. Like most other IPS TVs, its picture quality isn't that great due to poor contrast ratio and black uniformity. Its wide viewing angle is its strong point, but unfortunately, this TV doesn't excel at anything.

Our Verdict

6.6 Mixed Usage

Unfortunately, the LG UF6400 isn't a great TV. Movie lovers will find that the picture lacks some punch and gamers won't be satisfied with the responsiveness. Even if the TV is compatible with most PC inputs, the lag and somewhat-blurry 4k resolution will still make it a no-go. The only scenario where this TV could be viable is in an average-lit room with off-axis seating. For most people's needs, there is a better TV than this one.

See our Mixed Usage recommendations
  • 6.6 Mixed Usage
  • 6.1 Movies
  • 7.0 TV Shows
  • 6.9 Sports
  • 7.0 Video Games
  • 5.9 HDR Movies
  • 4.3 HDR Gaming
  • 6.5 PC Monitor
Pros
  • Good viewing angle
  • WebOS is a nice smart platform
Cons
  • Uses the less accurate RGBW 4k pixel structure
  • Poor picture quality in the dark
  • Does not excel at anything

Check Price

43" 43UF6400
Unavailable
B&H
49" 49UF6400
Unavailable
B&H

Test Results

Design
6.5
Design
Style
Curved No

It isn't a TV that will turn heads, but it doesn't look bad, either. The stand is very sturdy, but it will require a table almost as wide as the TV.

Design
Stand

Dimension of 49" TV stand: 28.6" by 8.2"

Design
Borders
Borders 0.74" (1.9 cm)

Design
Thickness
Max Thickness 2.52" (6.4 cm)

Picture Quality
6.3
Picture Quality
Contrast
Native Contrast
1181 : 1

This isn't the worst TV we have seen for blacks, but it is still near the bottom of the list. Blacks will look gray when you watch this TV in the dark.

0
Picture Quality
Local Dimming
Local Dimming
No
Backlight
Direct

5.9
Picture Quality
SDR Peak Brightness
SDR Peak 2% Window
262 cd/m2
SDR Peak 100% Window
262 cd/m2

6.2
Picture Quality
Gray Uniformity
50% Std. Dev.
6.324 %
50% DSE
0.201 %

There isn't much 'dirty screen effect' but the corners of the screen are very dark. This could be distracting while watching hockey, in particular.

6.2
Picture Quality
Viewing Angle
LCD Type
IPS
Color Shift
20 °
Brightness
30 °
Black Level
75 °

This is always the strong point of IPS TVs. The colors of the UF6400 don't lose much saturation when viewed from the side. This TV is suitable for a wide family room.

Update 01/06/2017: We have changed the methodology of testing. Since this is an old TV which we don't have anymore, we extrapolated the results from 2016 TVs.

6.7
Picture Quality
Black Uniformity
Native Std. Dev.
2.259 %

The black uniformity isn't that bad for an IPS TV, but most VA LED TVs will look better.

7.7
Picture Quality
Pre Calibration
White Balance dE
3.88
Color dE
4.2648
Gamma
1.88

9.7
Picture Quality
Post Calibration
White Balance dE
0.3
Color dE
0.6771
Gamma
2.21

8.0
Picture Quality
480p Input

DVDs will looks good once upscaled.

8.0
Picture Quality
720p Input

Cable TV and other 720p content also look good on this TV.

9.0
Picture Quality
1080p Input

Blu-rays looks sharp once upscaled.

8.0
Picture Quality
4k Input

This TV doesn't display true 4k resolution. It includes a white pixel in its pixel substructure. It isn't apparent from farther away, but can be obvious from up close, like if you use the TV as a PC monitor. Text can look blurry.

6.6
Picture Quality
Color Gamut
Wide Color Gamut
No
DCI P3 xy
74.28 %
DCI P3 uv
82.18 %
Rec 2020 xy
52.16 %
Rec 2020 uv
57.05 %

6.5
Picture Quality
Reflections
Reflection
1.9 %
Screen Finish
Semi-gloss

Direct light produces rainbow reflections.
While it can get bright enough, the TV isn't able to overcome strong light. It also get a yellow tint when there is a lot of light in the room.

0
Picture Quality
3D
3D
No
3D Type
No

Picture Quality
Pixels

The less accurate RGBW 4k panel of the LG UF6400 adds a white pixel, which can be seen in this close-up picture of the screen.

Motion
7.7
Motion
Motion Blur
Response Time
18.8 ms
Overshoot
0 ms

The motion blur isn't particularly bad, and it won't be a problem for most content.

2.8
Motion
Image Flicker
PWM Dimming Frequency
120 Hz
BFI
No
BFI Frequency
120 Hz
BFI In Game Mode
No

7.1
Motion
24p Playback
Judder-free 24p
Yes
Judder-free 24p via 60p
No
Judder-free 24p via 60i
No

For 24p sources like Blu-ray, the TV is able to remove judder correctly. Unfortunately, movies over cable or from some streaming services will still have judder inconsistently. Since this is a 60 hz TV and it has TruMotion, it can only interpolate signals under 60 hz.

5.0
Motion
Motion Interpolation
Motion Interpolation (30 fps)
Yes
Motion Interpolation (60 fps)
No

Inputs
5.9
Inputs
Input Lag
1080p @ 60Hz
56.1 ms
1080p With Interpolation
129.2 ms
1080p @ 60Hz Outside Game Mode
71.2 ms
1080p @ 60Hz @ 4:4:4
56.1 ms
4k @ 60Hz + HDR
N/A
4k @ 60Hz @ 4:4:4 + 8 bit HDR
N/A

Under game mode, the TV is responsive enough for casual gaming, but any hardcore players will feel a bit of lag on their controller inputs. Compared to other 2015 TVs, the input lag is average-high.

8.0
Inputs
Supported Resolutions
1080p @ 60Hz @ 4:4:4
Yes
1080p @ 120Hz
No
4k @ 30Hz @ 4:4:4
Yes
4k @ 60Hz
Yes
4k @ 60Hz @ 4:4:4
Yes

Most of the modes tested work on this TV except for 1080p@120Hz. To achieve 4k @ 60Hz turn on 'HDMI Ultra HD Deep Color'. To add chroma 4:4:4, enable 'HDMI-PC' under the picture menu. Unfortunately, if you use the TV as a PC monitor, the input lag (same as in game mode) will be quite apparent. Even more so for games like first person shooters, which require fast reflexes.

Inputs
Side Inputs

Inputs
Rear Inputs

Inputs
Total Inputs
HDMI 2
USB 1
Digital Optical Audio Out 1
Analog Audio Out 3.5mm 0
Analog Audio Out RCA 0
Component In 1 (shared)
Composite In 1 (shared)
Tuner (Cable/Ant) 1
Ethernet 1
DisplayPort 0
IR In 0
SD/SDHC 0

Inputs
Inputs Specifications
HDR10
No
Dolby Vision
No
5.1 Passthrough ARC Dolby Digital
Yes
5.1 Passthrough ARC DTS
Yes
5.1 Passthrough Optical Dolby Digital
Yes
5.1 Passthrough Optical DTS
Yes
HDMI 2.0 Full Bandwidth Yes
ARC Yes (HDMI 2)
USB 3 No
HDCP 2.2 Yes
CEC Yes
MHL No
Variable Analog Audio Out No

Sound Quality
6.5
Sound Quality
Frequency Response
Std. Dev. @ 70
4.55 dB SPL
Std. Dev. @ 80
4.75 dB SPL
Std. Dev. @ Max
7.64 dB SPL
Max
90.3 dB SPL
Low-end Cutoff
89 Hz

Poor frequency response, especially under heavy load, which seems to cause significant pumping and compression. The loudness and bass-extension are decent.

5.6
Sound Quality
Total Harmonic Distortion
Distortion @ 70
0.037
Distortion @ 80
0.116
Distortion @ Max
0.096

Decent distortion performance at all levels.

Smart Features
8.5
Smart Features
Interface
Smart OS WebOS

WebOS is a great smart TV platform and has a good amount of available apps. Unfortunately, you don't get the smart remote with this TV, so it isn't the best way to experience the platform. It takes more time to input text, but other than that, the navigation is straightforward. You can read our overview of LG's WebOS here.

0
Smart Features
Ads
Ad-free
No
Opt-out
No

Smart Features
Remote
Remote Basic

Smart Features
Misc
Power Consumption 36 W
Power Consumption (Max) 57 W
Firmware 03.10.21

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