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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  • inighthawki - Tuesday, March 31, 2015 - link

    You guys really need to get the hardware for measuring input lag. For most displays this would not be a big deal to not know, since most are reasonable for basic activities. But when reviewing a gaming display, this is a pretty critical thing to know.
  • Eidigean - Tuesday, March 31, 2015 - link

    I completely agree, input lag is very important. I still use my ZR30w IPS display which does not have a scaler or OSD, and the input lag is much lower than the Dell U3011.

    From Brian Klug's review...
    http://www.anandtech.com/show/4070/dell-u3011-revi...

    The U3011's scaler / OSD added 12ms of latency compared to the XR30w.
  • Souka - Tuesday, April 7, 2015 - link

    I game on a 24" Sony CRT computer monitor.... my lag is in nano-seconds. :)
    (Well, many years ago I was using one)

    Kinda miss those screens
  • willis936 - Tuesday, March 31, 2015 - link

    Honestly. It's months overdue. It's arguably one of the most important things to !measure on any display, let alone ones with gamer oriented features (cutting edge adaptive sync technologies).
  • jimjamjamie - Wednesday, April 1, 2015 - link

    I'll even disable uBlock for a few weeks to help raise funds.
  • Byte - Thursday, April 2, 2015 - link

    Darn almost peed my pants then saw it was only 1080. Was kinda surprised when i saw DP 1.2a and HDMI 1.3 but that explained it. Give us 1440 curved with freesync and its probably pinnacle for easily 5 years till OLEDs take over.
  • okashira - Thursday, April 2, 2015 - link

    I would have been embarrassed to post any kind of FreeSync or FreeSync vs Gsync review without exact input lag numbers.
  • blanarahul - Tuesday, March 31, 2015 - link

    *sniff* *sniff* Nobody cares about the high contrast ratio VA panels.
  • MrCommunistGen - Tuesday, March 31, 2015 - link

    I'd love to pick up a G-Sync or Freesync version of the BenQ BL3200PT if they could pull off even a slightly wider range of refresh rates than we see here in this review. 40Hz to 80Hz would allow them to double strobe every frame at 40Hz or below.
  • Samus - Wednesday, April 1, 2015 - link

    Interestingly, what I take away from this review, is AMD screwed up one of the benefits of G-sync, that is, the range of refresh. Even though this monitor is capped at 75hz, ie 75FPS, even with vsync off it should know better than to drop below 60FPS/60HZ because tearing is more annoying than judder at lower FPS because the tearing stays on the screen longer since the refresh rate is lower. That's a real oversight...

    Personally I just stick with 144hz panels (all of which are TN unfortunately) and always have vsync on. With a powerful enough card that never drops below 60+fps it is butter smooth and looks smooth as butter.

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