LG31MU97 4K Display
Related: 4K and 5K displays, color space and gamut, computer display, iMac, iMac 5K, MTF and Micro Contrast, Thunderbolt
The late-2014 LG 31MU97-B 31-inch 4K display offers an attractive price, size, and form factor for a true 4K display (4096 X 2160). To use the 31MU97, a computer capable of driving a 4K display is needed. For Macs as of late 2014, that means the 2013 Mac Pro, 2014 iMac 5K or 2013/2014 MacBook Pro.
Note: the full resolution requires the use of the supplied Mini DisplayPort to DisplayPort cable; a cable that otherwise works fine with 4K displays of 3840 resolution did not allow full 4096 resolution to function.
Image quality is gorgeous, particularly at a 2:1 eye-friendly display scaling of 2048 X 1080. The panel coating reminds of the NEC PA244UHD and has a very smooth but not shiny finish which makes the high resolution seem even more crisp. Your author greatly prefers it to the iMac 5K display, which is mirror-shiny.
The display made no audible noise and has no fan. A certain amount of unpleasant electronic odor was noticed at first, but this diminished after a few hours power on time; such odors are some sort of initial “bake in” off-gassing with many electronics.
Display settings in the on-screen menus
The following were used for evaluation:
- Function => Picture Mode = Adobe RGB.
- Screen => Super Resolution = OFF
- Screen => Uniformity = ON
- Screen => Response Time = Middle
Calibration and profile
The built-in display profile “31MU97” was used for general evaluation, which unfortunately totally kills the reds in images like this (red ripe strawberries, deep orange tones, mango). It appears to be an sRGB profile and there is only one profile listed. It is thus essential to calibrate and profile properly, but this was not possible due to software issues.
General discussion of
- The LG display offers 4096 X 2160 resolution in a 31-inch form factor (vs 3840 X 2160 in 32 inch as in the NEC PA322UHD). This makes the LG display slightly higher-res with slightly denser pixels. For video users, the true 4096-wide resolution is a decided plus.
- Like the NEC displays, the LG display “dead ends” the connection (no Thunderbolt data port daisy-chaining). So iMac 5K users (2 ports) eat one port to attach such displays, leaving only one (1) Thunderbolt port. However, the display should work at the end of the Thunderbolt chain and there are Thunderbolt docks to work around this issue.
- Actual gamut can vary greatly against specified official figures. For example, the NEC display gamuts tend to greatly exceed AdobeRGB gamut, into the reds and blues. So “98% of AdobeRGB” can mean very different things; that specification has to account for all color shades (some of which might not be reproducible), but it does necessarily not reflect superior gamut into some colors.
- For some professionals, color gamut and grayscale uniformity and tracking over time and temperature are all important. On the flip side, these can be fine points that are of little concern to many users, particularly those simply looking for a 4K display of reasonable size for general use.
- Claims of “hardware calibration” need to be borne out by actual results, supported properly with software and measurement hardware, etc. Moreover, calibration can be real (the display itself, true calibration in 14 bits including “3D LUT” support and so on), or faux calibration. Many users might be well satisfied with faux calibration, but in my experience over some years, I never found satisfaction with the stepping errors in dark tones using faux calibration.
- Warranty and support matter (and this can vary throughout the world): NEC support has been excellent in my experience, but your author has no experience on LG support.