LG UF6400  TV Review

Review updated Mar 01, 2017 at 06:31am
Tested using Methodology v1.0 
LG UF6400
6.6
Mixed Usage 
Value for price beaten by

Not at the latest test bench

6.1
Movies 
Value for price beaten by

Not at the latest test bench

7.0
TV Shows 
Value for price beaten by

Not at the latest test bench

6.9
Sports 
Value for price beaten by

Not at the latest test bench

7.0
Video Games 
Value for price beaten by

Not at the latest test bench

5.9
HDR Movies 
Value for price beaten by

Not at the latest test bench

4.3
HDR Gaming 
Value for price beaten by

Not at the latest test bench

6.6
PC Monitor 
Value for price beaten by

Not at the latest test bench

 0
 TV Settings
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.

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
5.9
HDR Movies 
4.3
HDR Gaming 
  • 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
  • 6.6
    PC Monitor
  • Changelog

    1.  Updated Mar 01, 2017: Review published.
    2.  Updated Dec 01, 2015: Our testers have started testing this product.
    3.  Updated Oct 25, 2015: We've purchased the product and are waiting for it to arrive in our lab.

    Check Price

    43"43UF6400
    SEE PRICE
    Amazon.com
    49"49UF6400
    SEE PRICE
    Amazon.com
    How We Test TVs

    We buy and test dozens of TVs yearly, taking an objective, data-driven approach to deliver results you can trust. Our testing process is complex, with hundreds of individual tests that take over a week to complete. Most of our tests are done with specially designed test patterns that mimic real content, but we also use the same sources you have at home to ensure our results match the real-world experience. We use two main tools for our testing: a Colorimetry Research CR-100 colorimeter and a CR-250 spectroradiometer.

    Test Results

    Sort:
    RATINGS
    Category:
    All
    Design
    6.5
    Style
    CurvedNo

    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
    Borders0.74" (1.9 cm)
    Thickness
    Max Thickness2.52" (6.4 cm)
    Picture Quality
    6.3
    Contrast
    Native Contrast
    1,181 : 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.

    0.0
    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
    6.3
    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.

    0.0
    3D
    3D
    No
    3D Type
    No
    Pixels
    TypeLED

    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 Blur
    Refresh Rate60 Hz
    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
    Inputs
    6.0
    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
    Resolution"4k"
    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
    HDMI2
    USB1
    Digital Optical Audio Out1
    Analog Audio Out 3.5mm0
    Analog Audio Out RCA0
    Component In1 (shared)
    Composite In1 (shared)
    Tuner (Cable/Ant)1
    Ethernet1
    DisplayPort0
    IR In0
    SD/SDHC0
    Inputs Specifications
    HDR10
    No
    5.1 Passthrough ARC Dolby Digital
    Yes
    Dolby Vision
    No
    5.1 Passthrough ARC DTS
    Yes
    5.1 Passthrough Optical Dolby Digital
    Yes
    5.1 Passthrough Optical DTS
    Yes
    HDMI 2.0 Full BandwidthYes
    ARCYes (HDMI 2)
    USB 3No
    HDCP 2.2Yes
    CECYes
    MHLNo
    Variable Analog Audio OutNo
    Sound Quality
    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.

    Smart Features
    8.5
    Interface
    Smart OSWebOS

    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.

    0.0
    Ads
    Ad-free
    No
    Opt-out
    No
    Remote
    RemoteBasic
    Misc
    Power Consumption36 W
    Power Consumption (Max)57 W
    Firmware03.10.21