HP Z27x Dreamcolor Professional Display Review

HP's new Z27x DreamColor supports all the important color gamuts and carries some distinctly unique features. This screen simply blows us away.

When you go sit down to watch a Hollywood blockbuster like Transformers: Age of Extinction or Edge of Tomorrow, most of what you see on the screen originated on a computer. CGI effects have come a long way in the past few years thanks to ever-faster computing platforms and improvements in display technology.

To properly master today’s digital films, artists need a color-accurate monitor that can easily switch between the major color, grayscale, and gamma standards currently in use. That means support not only for sRGB and Adobe RGB, but DCI (Digital Cinema Initiative) and Rec.2020 as well.

We’ve reviewed many screens that cover Adobe RGB. But only one other, NEC’s PA272W, can do DCI. Today, we’re checking out HP’s entry into the professional monitor market: its Z27x. This display not only covers the aforementioned three gamuts, it also supports a subset of Rec.2020, the new proposed standard for Ultra HD.

Panel Type & Backlight
GB-r-LED, edge array
Screen Size & Aspect Ratio
27-inch / 16:9
Max Resolution & Refresh Rate
2560x1440 @ 60 Hz
Native Color Depth & Gamut
10-bit / Adobe RGB+
Response Time (GTG)
7 ms
250 cd/m2
Video Inputs
2 x DisplayPort, 1 x HDMI
3.5 mm, Coax digital
v3.0: 1 x up, 4 x down
v2.0: 2 x down
Panel Dimensions
W x H x D w/base
25.5 x 16.6-21 x 9.5 in
648 x 443-536 x 241 mm
Panel Thickness
2.6 in / 65 mm
Bezel Width
.8 in / 21 mm
19.4 lbs / 8.8 kg
Three years

The technology in HP's Z27x is fairly unique among computer monitors. Its core panel is made by LG, like so many others. But this is not an off-the-shelf part. Modifications are made to the grid polarizer and backlight to improve upon both color accuracy and off-axis viewing quality.

As with other wide-gamut displays, the backlight is GB-r-LED. Green and blue LEDs shine through a red phosphor coating, allowing for a larger color gamut and greater accuracy from primary colors that have consistent spectral peaks. One drawback is that it’s difficult to achieve a perfect blue primary. Other GB-r-LED monitors we’ve measured do show either under- or over-saturation there. HP modifies the Z27x’s backlight with a custom blue LED to correct the issue. To help combat fatigue when artists have to pull an all-nighter editing images of Optimus Prime, constant-current (rather than pulse-width modulation) is used to control panel intensity. Add this display to the list of flicker-free products.

The other major change is in the grid polarizer. Every LCD panel, TN or IPS, focuses the light emitted by each pixel through a polarizing layer. Without it, you’d see a blurry image due to light spread, similar to how printing on certain types of paper can de-focus the picture coming from an inkjet printer. The dots enlarge and reduce clarity.

The grid polarizer is why LCD’s image quality degrades when viewed off-center. IPS is superior in this regard because its polarizer is much thinner than the one used in TN-based panels. HP tweaks its implementation further to improve off-axis quality in the vertical plane. Most displays we’ve photographed look fine from 45 degrees to the side, but not as good when viewed from 45 degrees above. The Z27x retains more detail and light output from that angle than other IPS panels.

There are many more features we’ll talk about as you read on. The Z27x is a direct result of feedback gained from artists at some of the top visual effects houses, and HP literally engineered the Z27x to meet their specific requests. Our own hands-on experience tells us this is a unique product with few, if any, equals, especially at its price point. Let’s take a look.

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