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Brightness & 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
There are a couple of distinct categories among ultra-wide panels, but we haven’t reviewed enough of them to create well-populated groups just yet. Most are marketed with gaming features, so that’s what we’re concentrating on today. From Acer we have the Z35 and X34 Predator models. LG also offers the 34UC98, and Asus is represented by THE PG348Q, an ROG screen. AOC’s C3583FQ represents a more budget-conscious mindset. All displays offer either FreeSync or G-Sync.
Ultra-wide panels have a challenge in spreading their output over a large screen area, so they aren’t usually as bright as their 16:9 counterparts. Nevertheless, all the panels here can manage over 300cd/m2. That’s plenty of light for gaming or any other endeavor. Monitors with blur reduction need a little extra juice to overcome the backlight strobe. The 38UC99 has sufficient horsepower to achieve that.
The difference between IPS and AMVA is clear in the black level test. The top-finishing Acer is more than 50% darker than the third-place X34. This allows for some serious contrast — well over twice that of the next best monitor. The only bummer is the 35" screens are stuck at 2560x1080 pixels for the moment. The 38UC99’s contrast is adequate, but at this price level, we’d like to see just a little more image depth.
Uncalibrated – Minimum Backlight Level
Lowering brightness to zero results in a perfect 54.7930cd/m2. We love playing games in the dark at low backlight levels. It really draws you into the on-screen environment when the room disappears completely. This light level is an ideal way to accomplish the effect. Black levels and contrast remain consistent at all backlight settings, which is what we’d expect from any panel regardless of price. The 38UC99 nails that particular standard.
After Calibration to 200cd/m2
The calibrated brightness and contrast results show the difference between FreeSync mode and 1ms Motion Blur Reduction. You can’t use both features at once. The backlight strobe will cost you 34% of your output, but there is an upside. Black levels are reduced by the same amount, which means contrast stays pretty close to the mark. The 38UC99 is the first blur-reduction-equipped monitor we’ve tested that can accomplish this feat. And brightness is independently adjustable, so you can max it for a total output of 205.6345cd/m2.
ANSI Contrast Ratio
Not only does ANSI contrast remain strong, it actually exceeds the calibrated sequential number. That’s a rarity among our review subjects, and it speaks to the high-quality panel in use here. It’s not surprising since LG makes the part themselves. The 38UC99 is a premium product that delivers solid engineering and consistent performance. Our only wish is that it could provide just a tad more overall contrast.
