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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  • hammer256 - Wednesday, April 1, 2015 - link

    Hm, just curious, which design philosophies are you speaking of?
  • Spoelie - Wednesday, April 1, 2015 - link

    NVIDIA ~ apple like, control the entire customer experience, at a price
    See this: http://www.forbes.com/sites/jasonevangelho/2015/03...

    AMD ~ open standards, it's the monitor baker's responsibility not to deliver a shitty display.

    Problem is that, for now, the entire G-SYNC experience is superior and no easy fix for that. See:
    http://www.pcper.com/reviews/Graphics-Cards/Dissec...
    http://www.tftcentral.co.uk/reviews/acer_xb270hu.h...
  • Crunchy005 - Wednesday, April 1, 2015 - link

    Windows open standards up to the computer baker to deliver good hardware, and up to all the hardware manufacturers to deliver good drivers. Apple computers do have a very nice benefit, although I feel still more open then nvidia at times. Although proprietary and closed isn't necessarily helping apple computers in the gaming world so controlling everything isn't always good.
  • Antronman - Tuesday, March 31, 2015 - link

    >Freesync
    >Ultrawide
    >14ms response time
    >$649 MSRP

    Who's going to buy this?
  • medi03 - Wednesday, April 1, 2015 - link

    People who were after dual monitor setup?
  • jabber - Wednesday, April 1, 2015 - link

    Quite handy for video editing enthusiasts too.
  • Antronman - Wednesday, April 1, 2015 - link

    Cheaper and higher resolution with two 1080 monitors.

    Same cost for two 1440p monitors.
  • sibuna - Wednesday, April 1, 2015 - link

    lots of people, I have the 34UM95 (no interest in any of the "sync" techs) the monitor replaces 2 27" 1440p monitors

    im never going back
  • bizude - Sunday, April 5, 2015 - link

    14ms *full* response time. 5ms GTG, which is standard. Not the fastest, for sure, but plenty fast enough for gaming. The only people who won't be satisfied by this response time are CS:GO addicts.
  • mobutu - Wednesday, April 1, 2015 - link

    You should really test this one, 144Hz IPS:
    There's one really good 144Hz IPS panel/monitor: http://www.tftcentral.co.uk/reviews/acer_xb270hu.h...

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