Dell S2721DGF 27-inch Gaming Monitor Review: Great HDR Value

For fans of color

Dell S2721DGF
(Image: © Dell)

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Grayscale & Gamma Tracking

We describe our grayscale and gamma tests in detail here.

In the default Standard picture mode, the S2721DGF has a slight green tint in the middle brightness steps. It’s hard to see in actual content but worth fixing. Gamma tracks extremely well with only a slight dip at the 10% step, indicating luminance that’s too high.

Calibrating the Custom Color mode (second chart) yielded a nice gain with all errors below the visible threshold. Gamma is unchanged, which is a good thing. Our only complaint is the lack of gamma presets. Since the S2721DGF has plenty of light output available, it would be nice to select a higher gamma value for more depth in the midrange and shadow areas. But with the available adjustments, the picture is still clearly improved in both depth and dimension.


The S2721DGF’s default grayscale error of 3.31 Delta E (dE) is just barely visible in both test patterns and content. The green tint is mainly in the midtones, where most image content lies. That puts it mid-pack in our comparison. 

After calibration, the Dell moved up to fourth place , but with all the monitors sporting low dE scores, the Dell won’t look any different than the other screens here.

Gamma tracking is excellent in either case. A 0.11 range of values is about as tight as it gets, and with a 2.19 average value, the S2721DGF is only 0.45% off the mark -- excellent performance.

Color Gamut Accuracy

For details on our color gamut testing and volume calculations, click here.

The S2721DGF shows excellent color gamut accuracy in its default state with a low 1.74dE average error. The chart shows nearly complete coverage of the DCI-P3 gamut with a little bonus red. It only comes up a tiny bit short of 100% green saturation. Overall, buyers seeking a very colorful monitor will be pleased. 

Calibration (second chart) improved the average error to the professional level and bumps up mid-tone red saturation a little ,which is a good thing. This is excellent performance.


A 1.01dE average gamut error  post-calibration is among the best we’ve recorded. The S2721DGF could function as a professional monitor for post-production color-critical tasks. The only thing that might be an issue is its lack of an sRGB mode. You can see in the second chart that it covers an excess 37.7% of that smaller gamut. But its 92.88% coverage of DCI-P3 is among the best.

Christian Eberle
Contributing Editor

Christian Eberle is a Contributing Editor for Tom's Hardware US. He's a veteran reviewer of A/V equipment, specializing in monitors.