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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
All OLEDs, including the 27QHD240, vary brightness according to the average picture level. That means a full-field white pattern will be dimmer than the 25% window I used for testing. A full field measured 192.5 nits, but the true peak white level is over 412. You’ll have to set the brightness by eye to suit your particular environment. I set the brightness slider to 80% in my brightly lit office for a comfortable image.
No matter what, black levels are truly black. They cannot be measured because the pixels are shut off and do not emit light. This yields an infinite contrast ratio, which can be seen in a visual comparison with another monitor. Viewed side by side against a Mini LED with its zone dimming engaged, the 27QHD240, like the other OLEDs, is clearly superior. It truly doesn’t get better than this.
After Calibration to 200 nits
For testing purposes, I set a 25% window pattern to 200 nits. In practice, I would use a higher brightness setting lest the image be too dim for my room. Your mileage will vary. Try a few different settings over a week or two to find the optimal level. Whatever you do, contrast remains the same with zero value black levels. ANSI contrast is also unmeasurable because the black squares in the checkerboard pattern emit no light.
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