LG 32UD99 Ultra HD HDR FreeSync Monitor Review

Grayscale, Gamma & Color

We narrowed the 16 picture modes down to three for our tests: Custom, Rec.709, and HDR Effect. The fourth set of charts indicates the calibration we performed in Custom. The other two presets are fixed and cannot be adjusted.

Grayscale Tracking

Our grayscale and gamma tests are described in detail here.

Most users, professionals included, will be just fine with the 32UD99’s Custom mode and its default settings. Our chart runs slightly blue, but all errors are below the visible threshold of 3dE. This is excellent performance, especially for the money. Rec.709 is slightly off the mark in the brighter steps, but still fine for pro-graphics tasks. HDR Effect is a personal taste mode and doesn’t conform to any established standards. Its grayscale is decidedly blue, which enhances the perception of brightness at the expense of color accuracy. As you’ll see below, it makes some changes to gamma tracking as well.

Calibrating the RGB sliders results in even better grayscale tracking with all errors under 1dE save the 0 and the 10% levels. It can’t get much better than that.


1.9dE is perfectly acceptable out-of-box performance for any professional monitor, and well within the data sheet provided with our sample LG 32UD99. Calibration is certainly unnecessary in Custom or Rec.709 modes, but if one can achieve .52dE, then why not? Our tweaks took all of 10 minutes and rewarded us with some of the best tracking we’ve ever recorded. This is excellent performance, especially at LG’s chosen price point.

Gamma Response

Gamma is a key factor for both SDR and HDR material. We’ll test the 32UD99’s actual EOTF on the next page, but we’re showing what happens in HDR Effect mode right here. There is dynamic contrast in operation, and we could see each test pattern shift as it was displayed. By slowing our measurement sequence, we got a good snapshot of the monitor’s luminance manipulation. Tracking stays relatively straight until 60%, where the light level rises more slowly. The visible effect makes the overall image look darker, except for the brightest highlights which pop out as they should. Some users may like this approach, others (us included) may not. Nothing will beat true HDR-encoded content of course, but this method is not without merit.

In both Custom and Rec.709 modes, gamma tracks the 2.2 power function closely on the Mode 2 preset. Adjusting the RGB sliders won’t impact luminance if you leave the Contrast slider at its default setting.


All the monitors here sport excellent gamma tracking, so differences are minor. The LG 32UD99 has a slightly greater range of values and misses the 2.2 spec by 5.45%, with a 2.08 average value. That’s mainly due to the shift between 60 and 90%, but we’re talking about a very slight error. We have no visual issues to report here.

Color Gamut & Luminance

The LG 32UD99 is a two-gamut monitor. Custom delivers DCI-P3, while sRGB and Rec.709 hit those standards with precision. If you want to tweak further in the CMS, you’ll have to work with DCI. The other two gamuts are not adjustable.

For details on our color gamut testing and volume calculations, please click here.

Thanks to excellent grayscale and gamma tracking, the LG 32UD99’s color saturation points are all in contact with their target squares. Only the magenta secondary is slightly out of phase before calibration. This is an invisible error, but it’s easily corrected with tweaks to the RGB sliders. The gamma preset is fine as is. The fixed Rec.709 mode has no visible errors in either the gamut or luminance charts. HDR Effect pulls red, magenta, and cyan off their hue targets, but keeps saturation levels reasonably close to the correct DCI-P3 points. Calibration results in an almost-perfect gamut and luminance result, with only 100% red showing a barely visible error.


1.77dE represents our calibration in the Custom mode. The default measurement is 2.16dE, which is visually indistinguishable from the adjusted figure. Rec.709 delivers 1.82dE, which is about as good as it gets for out-of-box performance. The most expensive monitor, Dell’s UP2718Q, is good at the default settings, but requires a software calibration to reach full potential.

Our 90.69% sRGB volume result surprised us a little. If you look closely at the charts, red and blue are slightly under-saturated. It’s enough to shave off that 9.31%. DCI-P3 volume doesn’t appear on the chart, but we measured it at 89.68%, a little under LG’s 95% claim. All monitors will benefit from a custom IEC profile. We recommend them for professional use in every case.

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