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Uncalibrated – Maximum Backlight Level
In the GP27U’s User 1 mode, I measured a peak white level of 451.8933 nits, more than enough for any work or play environment. The backlight can be adjusted over 100 steps, but 200 nits was setting 24, which means the minimum is a bit high at 64 nits. That’s a reasonable level for darkroom use. My only actual complaint is that below 200 nits, each click of the slider drops brightness by 3-5 nits. That’s a bit coarse for my taste. I would prefer to see finer control.
Black levels are IPS average, so the contrast is also average at 920.3:1. Local Dimming is available for SDR signals, increasing dynamic range significantly. Even on the Low setting, I couldn’t measure black, so contrast can be theoretically infinite.
After Calibration to 200 nits
Calibration improves contrast slightly to 991.1:1, moving the GP27U up to fourth place. Again, this is average IPS performance. The Samsung is well ahead of the pack because its local dimming is always engaged and cannot be disabled.
The GP27U maintains its contrast ratio in the ANSI test, which speaks to its engineering and construction. The grid polarizer is precisely fitted, maintaining high intra-image contrast and a sharp image.
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