LG 24GM77 24-Inch 144Hz Gaming Monitor Review

Results: Brightness And Contrast

To read about our monitor tests in-depth, please check out Display Testing Explained: How We Test Monitors and TVs. Brightness and Contrast testing is covered on page two.

Uncalibrated – Maximum Backlight Level

Today we’re stacking the 24GM77 up against five other high-speed gaming monitors. G-Sync-capable screens include AOC’s G2460PG and Asus’ ROG Swift PG278Q. Representing plain ol' 144Hz displays are AOC’s G2460PQU and two XL-series models from BenQ, the XL2430T and XL2720Z. Every monitor in the group offers motion blur-reduction by way of backlight strobing.

The 24GM77 is fairly bright at 359.5390cd/m², landing a tad over LG’s claimed 350cd/m² spec. Is it bright enough to back up the Motion 240 backlight strobe feature? Other screens reduce their output by half or more when using comparable functionality. And LG chooses not to include a pulse-width adjustment like the competition.

For the maximum backlight setting, this is a pretty good black level. With the latest games looking more and more like interactive film, deep blacks are an important facet of the experience.

The 24GM77 handily beats our preferred contrast ratio of 1000:1 and takes the top spot. High contrast is important, regardless of a monitor’s intended use. But in games and movies, we’d place a higher value on that than color accuracy.

Uncalibrated – Minimum Backlight Level

It’s always nice to turn off the lights and experience games and movies in total darkness. When you’re sitting two feet away, a quality image can really make the room melt away and pull you into a virtual world. The 24GM77’s minimum output of 66.6293cd/m² is a great way to make that happen.

The minimum black level stays solid relative to our comparison group. So far, we’re liking the LG’s image depth a lot. There’s plenty of punch available at all backlight levels, making this a particularly flexible display.

Minimum contrast drops only slightly from the max number. That consistency we look for in monitors at every price point is clearly evident. LG is using a high-quality panel in a value-priced display.

After Calibration to 200cd/m2

This is where we show you the effect of Motion 240. There is no adjustment for pulse width; it’s either on or off. As you can see, the drop in output is small (less than 15 percent). In fact, you can barely tell the difference when looking at actual content. Motion-blur, however, is quite obviously reduced. We checked out the tests available on Blur Busters and saw improvement in every instance. This is the best-implemented motion-blur reduction we’ve seen.

Unlike other screens, where backlight strobing only affects peak output, the 24GM77 takes a hit in black level too. It roughly doubles when Motion 240 is turned on. Fortunately, the monitor has excellent native contrast to begin with, so image quality is not significantly reduced.

Without Motion 240, calibrated contrast is a class-leading 1104.4:1. When you turn on the backlight strobe, contrast drops by almost 36 percent. The light output penalty is negligible, but you have to decide if the contrast reduction is worth it for a little less motion blur. There’s only one caveat to consider – when you turn on Motion 240, you can’t use the input lag-reducing DSA feature. We’ll show you that data on page seven.

ANSI Contrast Ratio

Though some enthusiasts would consider the 24GM77 a throwback, given its TN panel, the quality is certainly there. We haven’t measured many screens able to crack the 1000:1 barrier for ANSI contrast, regardless of technology. We’d have no trouble using this monitor for any computing task. It’s not just for entertainment.