Reviewed on Dec 03, 2015

LG UF6400 TV REVIEW

Usage Ratings - Version 1.0
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.

Test Results
Design 6.5
Picture Quality 6.7
Motion 7.1
Inputs 6.2
Sound Quality 6.2
Smart Features 8.5
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

6.5

Design

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.

Stand

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

Borders
Borders : 0.74" (1.9 cm)

Thickness
Max Thickness : 2.52" (6.4 cm)

6.7

Picture Quality

Because of its poor blacks and contrast, movies won't be great if you watch them in a dark room. With the lights on, this won't be as big of a problem. The TV is judder-free if you watch Blu-ray discs, which is great.

6.3 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 Local Dimming
Local Dimming
:
No
Backlight
:
Direct

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

6.2 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 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 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 Pre Calibration
White Balance dE
:
3.88
Color dE
:
4.2648
Gamma
:
1.88

9.7 Post Calibration
White Balance dE
:
0.3
Color dE
:
0.6771
Gamma
:
2.21

8.0 480p Input

DVDs will looks good once upscaled.

8.0 720p Input

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

9.0 1080p Input

Blu-rays looks sharp once upscaled.

8.0 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 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 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 3D
3D
:
No
3D Type
:
No

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.

7.1

Motion

Here again, the LG UF6400 is average. The motion blur trail isn't too long, but the uniformity of the screen is bad, which could be apparent on playing surfaces, since those are mostly solid colors.

7.7 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 Image Flicker
PWM Dimming Frequency
:
120 Hz
BFI
:
No
BFI Frequency
:
120 Hz
BFI In Game Mode
:
No

7.1 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 Interpolation
Motion Interpolation (30 fps)
:
Yes
Motion Interpolation (60 fps)
:
No

6.2

Inputs

Only casual gaming would be suitable on this TV, since the input lag is average-high. Any competitive gaming should be avoided. The lag is even more apparent when using the TV as a PC monitor. Combined with the fact that 4k doesn't look that sharp up-close, this TV wouldn't be great as a PC monitor (even though it is compatible with most PC inputs).

5.9 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 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.

Side Inputs
Rear 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 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

6.2

Sound Quality

The sound of the LG UF6400 is like that of most other TVs. It can get loud enough without much distortion, but anyone who cares about sound would benefit from using a dedicated soundbar or speaker system.

Note: Sound Quality test for TVs reviewed before 2017 was performed at 75dB, 85dB, and Max SPL. Starting 2017, the target SPL levels have been changed to 70dB, 80dB, and Max dB SPL.

6.5 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 Total Harmonic Distortion
Distortion @ 70
:
0.037
Distortion @ 80
:
0.116
Distortion @ Max
:
0.096

Decent distortion performance at all levels.

8.5

Smart Features

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 Ads
Ad-free
:
No
Opt-out
:
No

Remote
Remote : Basic

Misc
Power Consumption : 36 W
Power Consumption (Max) : 57 W
Firmware : 03.10.21

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.

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