Asus ROG Swift PG278Q 27-inch G-Sync Monitor Review

Results: Grayscale Tracking and Gamma Response

The majority of monitors, especially newer models, display excellent grayscale tracking (even at stock settings). It’s important that the color of white be consistently neutral at all light levels from darkest to brightest. Grayscale performance impacts color accuracy with regard to the secondary colors: cyan, magenta, and yellow. Since computer monitors typically have no color or tint adjustment, accurate grayscale is key.

User is the default color temp mode and it’s pretty close to correct. The RGB Balance chart shows a tendency towards red, but all of the errors are under three Delta E and therefore very hard to see. Even still, we observed an improvement after calibration.

Adjusting the RGB controls gives us a better result that is now under two Delta E across the board. You give up a tiny bit of contrast, but we think it’s worth it.

Here is our comparison group:

A Delta E measurement of 2.42 puts the PG278Q near the top in out-of-box grayscale performance. In fact, its result exceeds a few professional-class monitors we’ve tested. We feel most gamers would be satisfied with the Swift in its uncalibrated state.

A little adjustment brings the average error down to 1.27 Delta E. The improvement in image quality is noticeable to our eyes. When you always use a calibrated monitor, a display with even a tiny error doesn't look quite right. Today though, the grayscale prize goes to BenQ's XL2720Z with its stellar numbers.

Gamma Response

Gamma is the measurement of luminance levels at every step in the brightness range from 0 to 100 percent. This is important because poor gamma can either crush detail at various points or wash it out, making the entire picture appear flat and dull. Correct gamma produces a more three-dimensional image, with a greater sense of depth and realism. Meanwhile, incorrect gamma can negatively affect image quality, even in monitors with high contrast ratios.

In the gamma charts below, the yellow line represents 2.2, which is the most widely used standard for television, film, and computer graphics production. The closer the white measurement trace comes to 2.2, the better.

The gamma tracking runs just a tiny bit light at an average value of 2.15. It’s only slightly off of our standard and again, most users won’t notice. We do wish there was a gamma adjustment, however. Some games benefit from a little lighter or darker tone to help bring out detail. Fortunately, many developers add a software-based slider to compensate.

Here is our comparison group again:

The difference between the highest (2.29) and lowest (2.07) values is pretty small, indicating good tracking. There aren’t any significant dips or peaks to spoil the result.

We calculate gamma deviation by simply expressing the difference from 2.2 as a percentage.

A 2.15 average puts the PG278Q in fifth place among today’s group. Overall, we’re perfectly satisfied with its gamma performance. Our only beef is the lack of additional presets.

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. Christian began his obsession with tech when he built his first PC in 1991, a 286 running DOS 3.0 at a blazing 12MHz. In 2006, he undertook training from the Imaging Science Foundation in video calibration and testing and thus started a passion for precise imaging that persists to this day. He is also a professional musician with a degree from the New England Conservatory as a classical bassoonist which he used to good effect as a performer with the West Point Army Band from 1987 to 2013. He enjoys watching movies and listening to high-end audio in his custom-built home theater and can be seen riding trails near his home on a race-ready ICE VTX recumbent trike. Christian enjoys the endless summer in Florida where he lives with his wife and Chihuahua and plays with orchestras around the state.