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HP ZR2740w Versus Asus PB278Q: QHD 27" Monitors, Tested

Results: Viewing Angle And Uniformity

For off-axis viewing, there’s no better tech right now than IPS. You can sit as much as 45 degrees from center and still see a decent image. The light falloff is minimal, and the color shift associated with TN monitors is virtually non-existent.

Since the ZR2740w utilizes the LG H-IPS panel as its core, great off-axis performance is expected, and our photo shows that it doesn’t disappoint. Now that we’re showing step patterns, it’s easier to see when detail and light output are reduced as you move off-center. The HP maintains detail at the lowest and highest brightness levels with no perceptible color shift.

Here’s the Asus PB278Q:

Predictably, the Asus looks very similar in its viewing angle photo. Since the base panel is the same as Samsung’s excellent PLS monitor, the S27B970D, you can expect the same top-notch off-axis performance from the PB278Q. Once again, IPS proves itself to be the best currently-available technology for off-center viewing.

While some monitors are better than others, no LCD panel has perfect screen uniformity, and even samples of the same model can have quite a bit of variation. So, since there’s no fair standard for applying a rating to different monitors, we’ll simply present the results of our measurements.

To measure screen uniformity, zero percent and 100 percent full-field patterns are used, and nine points are sampled. We’re now expressing the values as percentages relative to the center of the screen.

HP ZR2740w
Black Field Uniformity
White Field Uniformity

Except for a slight hotspot at the lower-right corner, the ZR2740w does pretty well for black field uniformity. Its white field uniformity is even better with no visible variation except for a slightly dim upper-right corner.

The PB278Q, meanwhile, doesn’t fare quite as well.

Asus PB278Q
Black Field Uniformity
White Field Uniformity

In a full black field pattern, there is a visible bright area across the bottom of the screen. Thankfully, this doesn’t translate to the white field pattern, which looks quite good to the naked eye.

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.

  • KOKing
    I've had one of these HPs at work for a couple of months (replacing an early 24" 1920x1200 IPS), which I've set fairly low), but as this review says, it's not really necessary. I was a little disappointed that, possibly because of the aspect ratio change to 16:9, it doesn't _feel_ like a lot more screen real estate.
  • Immoral Medic
    Add 120hz, THEN it's enthusiast level.
  • bit_user
    Where are all the OLED monitors? They should be cheap and plentiful, by now!
    Useless review, the uniformity on these screens is pathetic, tried three of each, the color temp difference across the screen is over 1000K. Toms has very poor reviewers, only and do reliable screen reviews. And btw the U2713HM is regularly on sale for $500 or so, the ZR2740W is now an overpriced relic lacking even an OSD.
  • cangelini
    SIDDHARTH MISHRAUseless review, the uniformity on these screens is pathetic, tried three of each, the color temp difference across the screen is over 1000K. Toms has very poor reviewers, only and do reliable screen reviews. And btw the U2713HM is regularly on sale for $500 or so, the ZR2740W is now an overpriced relic lacking even an OSD.Screen uniformity is covered on page eight, and low points on both screens are discussed.
  • flong777
    Am I right by saying that the Asus monitor has more accurate color and better grayscale performance.
  • Marcus52
    Surprised that the Asus has slightly better lag results, as one of the reasons for not having an OSD is to reduce lag, and it can make a big difference. Of course, how you measure lag can get different results, and I've seen much lower numbers for the ZR2740w:

    tftcentral is showing the HP as having far less lag than the Asus panel.
  • ceberle
    The Asus certainly calibrates better than the HP; mainly because it can be calibrated. The HP is slightly better out of the box for grayscale and its chromaticity is also a touch better. Both screens have identical color to the eye. Only the instruments can tell the difference.

  • ceberle
    Regarding the lag results: It's hard to compare numbers from one review to another when the testing methods are so different. With our high-speed camera procedure, the only fair comparison is between the monitors we've tested. I would defend our response test as definitive though. Actually watching the screen draw in slow motion leaves no room for interpretation. The lag test is also consistent since we use the same signal chain for every screen. There is never a change in video cards, drivers, peripherals or any other device that might affect the result.

  • dgingeri
    I have the HP ZR2740w, and have for over a year now. It's a great looking monitor, and it performas well by my standards, but suffers from a significant lack of both reliability and support. HP's support is massively fragmented. It took me over three hours on the phone to get to the department that actually handled the support for this monitor. (It is a "Commercial" monitor, not business or personal. It's splitting hairs mighty thin, but that's the way HP's support is separated out.) When I finally got through, they sent a tech with a replacement monitor the next day. However, it also has two major hardware issues that render it useless when they occur. Most of the first run monitors had the power supplies die within months. The second run monitors had a serious issue with the control boards. All of them have issues with the USB hub, but it least the monitor keeps working if you don't have the USB cable plugged in. As an owner of one, I would not, under any circumstances, recommend this monitor to anyone.

    HP: the perfect example of a company falling apart because it is both too big and too fragmented.