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To read about our monitor tests in-depth, please check out Display Testing Explained: How We Test PC Monitors. We cover brightness and contrast testing on page two.
Uncalibrated – Maximum Backlight Level



AOC rates the CU34G3S at 300 nits, but I could not find that value in any of the Eco or game modes. This isn’t the brightest monitor out there, but it is bright enough. Large screens like this don’t need a ton of light output for SDR content. The only bummer is that there isn’t any more brightness for HDR material.
With deep blacks, the CU34G3S delivers excellent contrast of over 3,300:1. That’s good enough for third place here though, in the larger picture, it is higher than average among all the VA panels I’ve tested.
After Calibration to 200 nits



I didn’t calibrate the CU34G3S; a change in brightness to 200 nits was the only adjustment I made. The other monitors had their RGB sliders tweaked to remove grayscale errors. That slightly levels the playing field but still puts the AOC in a strong position. Obviously, the IPS-based BenQ is at a disadvantage here.
The CU34G3S’s ANSI contrast score stays over 3,100:1, which is excellent performance. Though it is a value-priced display, it doesn’t skimp on component selection or quality control. The image has lots of depth, true blacks with strong highlight and shadow detail, and well-saturated color.
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