LG 34UM67 sRGB Data and Bench Tests

For color accuracy, we test before and after calibration. For calibration, we use SpectraCal CalMAN with our own custom workflow. We target 200 cd/m2 of light output with a gamma of 2.2 and the sRGB color gamut, which corresponds to a general real-world use case. We use an i1 Pro provided by X-Rite. All measurements use APL 50% patterns except for uniformity testing, which uses full field.

LG 34UM67 Pre/Post Calibration
Pre-Calibration,
200 cd/m2
Post-Calibration,
200 cd/m2
Post-Calibration,
80 cd/m2
White Level ( cd/m2) 201 198.7 79.3
Black Level ( cd/m2) 0.2056 .2153 .0977
Contrast Ratio 978:1 923:1 811:1
Gamma (Average) 2.18 2.21 2.21
Color Temperature 6558K 6548K 6482K
Grayscale dE2000 2.94 0.38 0.99
Color Checker dE2000 2.49 1.24 1.39
Saturations dE2000 2.14 1.07 1.17

Before calibration, the LG 34UM67 has a slight blue tint to the grayscale but nothing too noticeable – especially for gaming purposes. Tweaking the OSD settings to 53/50/47 RGB gives a result reasonably close to the ideal 6504K color target. The grayscale errors are all under 4.0 dE2000, which is potentially visible but not overly so, with an average error level of 2.9 dE2000. The gamma curve isn’t great, starting high and ending low but with an average of 2.18 that’s close to our 2.2 target, so things can definitely be improved. Moving to colors, there are a few larger errors of nearly 5.0, mostly in the yellows and oranges. Some of these are due to the gamut falling slightly higher than sRGB, leading to some oversaturation of green and red.

Post-calibration the gamma and RGB balance are almost perfect. The average grayscale dE2000 falls to well below 1.0, which is invisible to the naked eye. Colorchecker and saturation accuracy improves as well, though there are still colors in the 4.0 range. Again, it’s mostly shades of yellows, oranges, and some greens that cause problems, which unfortunately tend to be the worst colors to have wrong for imaging professionals. Overall it’s a good monitor, and the target audience clearly isn’t going to be imaging professionals, so with or without calibration it will do well for gaming, movie watching, and other general tasks.

Changing to 80 cd/m2, the calibration results remain pretty consistent. The dE2000 numbers are slightly higher, but if the small change in accuracy is a concern then potential buyers would have already passed on this display. Only the most finicky of regular consumers might find something to complain about.

It’s also worth quickly discussing some of the other color modes, just because certain ones can be so far off that it’s a wonder anyone would even consider using them. LG offers four picture modes (Photo, Cinema, Reader 1, and Reader 2). Photos has a strong blue tint with average grayscale dE of 6.4 and many values nearing 10.0, though colors aren’t quite so bad averaging closer to 5.0. The Cinema mode is pretty close to the Custom setting, so while it’s tinted blue the grayscale dE is 2.3 while the colors average close to 4.0, with skin tones often falling into the 6.0+ range. Reader 1 and 2 are supposed to be more like print, with the results being heavily red biased with limited blue, and minimum black levels are much higher (2.5 cd/m2). The resulting grayscale dE2000 of 10.8/8.7 and average colors of 7.5/6.0 however are not particularly useful.

And that sums up why NVIDIA didn’t bother with supporting specialized color modes on their G-SYNC module: doing one color mode properly is generally more useful than supporting multiple incorrect color modes. While some people might appreciate the ability to quickly switch between various color modes, most just set up a display for everyday use and leave it be. Most named presets other than “standard” or “custom” end up being bullet points more than anything useful.

LG 34UM67 Brightness and Contrast LG 34UM67 Display Uniformity
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  • FlushedBubblyJock - Thursday, April 2, 2015 - link

    So freesync is low fps sunk.
    Another amd failure, no surprise there.
    Plus high fps sunk.
    Just a tiny near worthless middle ground - again...

    Now you know why nVidia actually made technology happen with new hardware, while amd claimed it is everyone else's job to do it, to make it work for amd.
    Freesync is only free for amd, no one else.
  • FlushedBubblyJock - Thursday, April 2, 2015 - link

    Don't forget it doesn't work with most games because the aspect ratio is wrong.
    ROFL
    Epic failure # xxx for amd.
    I can hear it now- "It's not amd's fault"... blah blah blah blah - yeah they sure "worked with" the "industry" didn't they. There's probably a boatload of unresponded to emails and phone messages sitting in the mad to do box - well too late again amd.
    It's someone else's job, right...
  • Black Obsidian - Thursday, April 2, 2015 - link

    So... because this one monitor isn't to your liking, FreeSync is an "epic failure" for AMD? That's some stellar logic right there.

    Those not hopelessly poisoned by fanboi-ism will note that there's no lack of released and pending FreeSync monitors running a wide range of sizes, aspect ratios, refresh rate ranges, and panel technologies.
  • wigry - Thursday, April 2, 2015 - link

    Whats wrong with 21:9 aspect ratio? All but the oldest games have no problem taking full use of this aspect ratio. Have managed to enable it on may of my old favorites and new games have no trouble with it whatsoever. So 21:9 aspect is nothing to be afraid of.
  • bizude - Thursday, April 2, 2015 - link

    You're an idiot. 99% of games out there work flawlessly with 21:9 monitors.
  • AnnonymousCoward - Saturday, April 4, 2015 - link

    "flawlessly"? No, 99% of the games listed here are not Hor+ Native. http://www.wsgf.org/mgl?page=1
  • bizude - Sunday, April 5, 2015 - link

    And that list is flat out wrong. For example, it lists AC 1 & 2 as not supporting ultra-widescreen, but both of them work with ultrawidescreen resolutions "out of the box". If you'd like, I can take screenshots for you.
  • AnnonymousCoward - Saturday, April 4, 2015 - link

    Jarred,

    -Watch out for overdrive. I think on the older Samsungs with it, it made input lag horrendous. Overdriving might always require at least 1 extra frame of buffering/processing.

    -For gaming, I think the higher the color gamut the better. Allowing a full range of saturated colors is more realistic for your eyesight. I see it as ok for 3D rendering, which is different from viewing pictures saved on a reduced gamut space.

    -It's inexcusable to have no height adjustment on a huge monitor like this one.

    -For general desktop use, the AOC Q2770PQU 27" 2560x1440 seems better. Vertical space is too important.
  • Ethos Evoss - Saturday, April 4, 2015 - link

    AMAZING !
  • mlmcasual - Monday, April 6, 2015 - link

    1080P=FAIL...

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