LG’s 31MU97 isn’t the most popular of monitors, it hasn’t even been reviewed by the biggest in technology reviewers and can probably be called one of the most peculiar screens we’ve ever used.
The screen does not have the normal 16:9 resolution but comes with a 256:165 one, at 4096×2160 pixels. This is similar to the 4K DCI standard meant for movies, and results in two (be it very small) black bars on either side of the screen when viewing 16:9 material. A 21:9 movie however looks slightly better on this screen due to the better fit, but black bars on top and bottom of screen will still be there.
This is not the only unique feature of the 31MU97, as this screen also supports the AdobeRGB colour space and is relatively cheap compared to the competition. An interesting screen to say the least.
LG has chosen to mount the 31MU97 on a solid stand that might look a bit delicate, but definitely is not. A VESA mount is present as well should you want a different option to attach your screen. The screen can be moved in height, tilt and rotate to portrait mode but strangely enough can not swivel on the stand.
All connections are placed so that they point downwards, and we find two HDMI, two DisplayPort (one mini) and a USB 3.0 hub with one upstream and three downstream ports, as well as an audio out. The screen also features two built in 5W speakers.
The OSD can be used through a joystick that is placed at the bottom of the screen. It works, but not as intuitive as we have seen with other manufacturers. All functions that you would want are present, including PiP/PbP and extensive options for changing the colour reproduction. LG does offer its own software that can help calibrate the screen more easily and even control the windows when using PiP or PbP. Another unique function is the ability to show one half of the screen as the sRGB colour space and the other half in full AdobeRGB. This is a very useful feature for working with material that is published on line as well as on paper.
LG calibrates the 31MU97 in the factory, as it does with most off their screens that are made in 2015, only the very cheap consumer models are non calibrated. As this screen can handle both sRGB and Adobe RGB we test it in both modes.
In the sRGB mode we can see that on the grey curve red is too low and both green and blue are too high when the percentage of white increases. This is also visible on the screen as it displays a cyan hue that is visible from 50% white. The average gamma is not bad with a value of 2.17 and the individual measurement points are not far off the ideal value of 2.2 but overall the screen is set just a little bit too low. Even though this is only small issue, we would have expected better from a screen that comes calibrated out of the factory. The average deviation on the grey is also a bit on the high end with 4,9 mΔuv, again we would have expected better from a calibrated screen.
The bad news ends with the above, as the colour reproduction of the screen is excellent. Only the colours green and yellow are slightly outside the preferred range, the average deviation on colour is 1,9 mΔuv which is extraordinarily low. The colour temperature is a bit high with 7259 K and this is clearly caused by the colour red that is set just a bit too low. The main issue with colour reproduction however are the yellow and green, they should have been set better.
When we look at the gamma curve on the AdobeRGB setting the results are a lot better, but again red is set too low. The average deviation is 4,5 mΔuv, the average gamma is 2,16.
On the AdobeRGB setting the screen sets an excellent result with a score of 1,6 mΔuv. The AdobeRGB scale is being shown just shy of perfect. The high colour temperature and the accompanying blue hue are still there but you can basically plug this monitor in and work with any application without having to change any setting.
The price of the LG 31MU97 is as we have already stated surprisingly low. The screen can be found under £ 900, not the cheapest around but no other screen in this price range is able to produce the full AdobeRGB range. The only other screen in this test that is able to do this is a lot more expensive, the LG offers excellent value for money and the minor negatives are outweighed by the low price.