The LG LF5800 is not a good TV. It has a good viewing angle, but nearly every other aspect of the picture quality is below average. It has poor blacks in a dark room and reflects too much light in a bright room.
As with a lot of LG TVs, the contrast ratio is sub-par. When you have the lights off, the black color appears gray.
The corners are darker than the center of the screen. Also, the top and bottom edge are brighter than the rest.
The main upside of the LG LF5800 is its wide viewing angle. You need to sit at a very wide angle to notice discoloration.
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.
The top and bottom border is brighter in dark scenes. Our unit also had a spot of clouding on the right side.
DVDs and SD content looks good on this TV, without the soft look found on the similar LG LF5600.
The LG 42LF5800 reflects a lot of light. Bright objects also have a rainbow glare around them.
It also doesn't get very bright, so it's a poor choice in a room with windows.
The transition of the pixels overshoots, creating a whiter trail behind moving objects. At least this shortens the length of the motion blur trail.
There is no judder in movies when watching them over 24p (Blu-ray players usually). However, it cannot do the reverse 3:2 pulldown. Also, it is only a 60hz, but at least it has motion interpolation.
If you play video games, set the mode to Game to get input lag of 49.6 ms. To get chroma 4:4:4, you will need to set the label of the input to PC. Note that doing so increases the lag to 59.9 ms.
Set the label of the HDMI input to PC to enable chroma 4:4:4 subsampling.
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.
Poor frequency response which gets even worse under heavy load. It doesn't get loud, either. The low-end cut off, however, is decent for a TV.
Good distortion levels all around, and there's not a significant increase under heavy load. But the TV doesn't get loud.