HP Omen X 25f 240 Hz Gaming Monitor Review: Speed and Style

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Grayscale, Gamma and Color

The Omen X 25f comes set to its Gaming picture mode, which offers accurate color without need for calibration. You can adjust the RGB sliders and gamma presets in this or any image mode.

Grayscale and Gamma Tracking

We describe our grayscale and gamma tests in detail here.

Our i1 Pro spectrophotometer shows a slight blue error in the Omen X 25f’s grayscale tracking but resulting deltaE (dE) values are below the visible threshold. We consider this sufficient accuracy to put the monitor on our Calibration Not Needed List. Gamma tracking is a tad light with an average value of 2.13.

After calibration, the grayscale error dropped below 1dE average, and gamma became ever-so-slightly lighter. The 2.4 gamma preset produced a darker presentation that may be appropriate for brighter games or videos. And you can switch between 2.2 and 2.4 without affecting grayscale tracking. It’s a matter of personal preference; we stuck with 2.2 for our testing.


With a 2.11dE grayscale error out of the box, the Omen X 25f ranks highly among super-fast gaming monitors for grayscale accuracy. Both it and the Acer make it onto our Calibration Not Needed list. But after applying a few tweaks, they dipped under the magical 1dE level, making them equal with most professional monitors. This is excellent performance for any screen.

While we rate the gamma tracking as slightly light after calibration, it’s consistent with a tight 0.14 range of values. We couldn’t achieve an exact 2.2 result with the included presets. The 2.4 option measured 2.33 on average. That value works for games and movies that are inherently bright. You’ll also get a little more color saturation, but shadow detail will be harder to see. We preferred 2.2 for our purposes.

Color Gamut Accuracy

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

We have no complaints about the Omen X 25f’s out-of-box color gamut accuracy. All points are in contact with their target boxes except magenta, which has a slight hue error. Grayscale calibration brought that secondary color closer to perfection. You can see that red is a tad under-saturated at first, and our calibration improves that primary a little. You can improve it further by changing the preset to 2.4, but that may make other areas of the image too dark. Our suggestion: try both and see which best suits your environment and preferred content.


Calibration took the color error from 2.06dE to 1.56dE. Though that seems small, it makes a visible difference in color saturation. Fixing the magenta secondary also contributes to a better image. If you don’t have the equipment for calibration, our recommended RGB settings will get you there. Even without adjustment though, the Omen X 25f has very good color accuracy.

sRGB coverage is slightly over 100%, due to a little bonus red and green. Though they are not oversaturated, they are slightly darker in hue. If you intend to do any color-critical work, a custom profile would be a good idea.

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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.