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 greater depth and pop. 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 accepted standard for television, film, and computer graphics production. The closer the white measurement trace comes to 2.2, the better.

The HP’s gamma rides right around the 2.0 mark, which is a bit lower than the 2.2 standard. This results in an image with slightly less perceived contrast, especially in darker content where the gamma value is below 2.0. The tracking is reasonably flat, which is a plus. If HP added a gamma control, this issue could be fixed easily.
The DoubleSight also lacks a gamma selector. Let’s see how it turned out.

The DS-309W seems to be the opposite of the HP. The gamma is fine at the lowest signal levels and gradually rises to over 2.5 at the 90 percent point. This is a small error, and one that should be nearly invisible to the naked eye. Nevertheless, the DoubleSight’s tracking is not quite as good as the HP screen.
Here’s how our 30-inch panels compare to the 27-inch competition.

With a range of values spanning as high as 0.38, both monitors finish at the back in this metric. While their gamma tracking is fair, it isn’t quite as good as the other five screens.
By expressing the gamma error in percentage of deviation, rather than showing the absolute value, it’s a little easier to compare the performance of all the monitors.

With a low average value of 1.83, the HP ZR30w finishes last in gamma performance. The DoubleSight fares better because it sticks closer to the correct 2.2 standard. Its overall error is extremely small compared to the Auria and the HP.
ANSI Contrast Ratio
Another important measure of contrast is ANSI. To perform this test, a checkerboard pattern of sixteen zero and 100 percent squares are measured. This is somewhat more real-world than on/off measurements because it tests a display’s ability to simultaneously maintain both low black and full white levels, while factoring in screen uniformity. The average of the eight full-white measurements is divided by the average of the eight full-black measurements to arrive at the ANSI result.

The HP’s ANSI number comes in a little lower than its on/off measurement. It is still quite high, however, at over 750 to 1. Only the 27-inch HP and the Asus QHD monitor from our last review do better in this test. The DoubleSight’s ANSI contrast is only a bit below its on/off number. This demonstrates consistent performance regardless of image content. In use, both panels look very good whether watching video, playing games, or working with productivity applications.
- 30 Inches And 2560x1600: Two Big-Screen Monitors
- Measurement And Calibration Methodology: How We Test
- Results: Stock Brightness And Contrast
- Results: Calibrated Brightness And Contrast
- Results: Gamma And ANSI Contrast Ratio
- Results: Grayscale Tracking
- Results: Color Gamut And Performance
- Results: Viewing Angle And Uniformity
- Results: Pixel Response And Input Lag
- 30-Inch QHD, Is Bigger Better?
Isn't the ASUS PQ321 already out along with a few other 4K monitors? granted price is a whole other story
You seriously can't see the pixels? I can see them on a 27" 2560x1440, which has smaller pixels. The .25mm range is adequate to me, but really I'd prefer something smaller than the .233mm on the 2560x1440.
When considering something like this for games, don't forget the cost of the video card(s) needed to drive it. A HD7750 may be "sufferable" even up to 1920x1080, but I'm not sure even a HD7770 or GTX650Ti could play newer games on better than "low" settings on one of these.
I have a ZR30W myself, and I would NEVER trade it unless what I'm upgrading to has more than a 2560x1600 resolution.
I've played on all sorts of monitors, and resolution trumps all other specs, unless you're dealing with 30fps or something...
I really wish I would have spent 1200$ on it long ago. Battlefield 3 and other highly graphical games are comparable to nothing else in the world.
The 60hz is not "old tech", it's more than sufficient to run games smoothly if vertical sync is on (even still when it's off). 60 fps is fine, television (pre hd) was 28hz. Anything above 60fps you really don't notice too much.
Oh, and for those looking for 4k tv's to use (I'm way ahead of ya) they only have 30hz refresh rates over the HDMI 1.2 port. We're going to have to wait for the tv's to add another port, wait for the upgrade to HDMI 2.0, or wait for some other solution.
We aren't going to see many 16:10 in the future. the 4K stuff is going to be 16:9 unless someone makes the move to stick with 16:10. However, the difference when it comes to 16:9 with a 2560x1440 and 16:10 2560x1600 is very minimal unless you really really need that extra height!
A properly implemented OSD would blend overlay pixels on-the-fly and add less than 100ns of lag to the process, which would be undetectable. The Viewsonic VP2770 has an OSD and is on par with the fastest LCDs in this roundup for total input-output lag. Having an OSD does not equate to lag.
The art of zero-lag OSDs is very old: countless computer CRTs from the mid-90s have it and TVs have had it for even longer. The OSD locks timing with the H/V sync and substitutes its signal over the relevant areas on-the-fly. With LCDs, this is even easier to do since everything is digital.
What is more likely happening is that "laggy" LCDs are doing extra image processing/enhancement or power-saving tricks such as dynamic brightness adjustments. For dynamic backlighting (power saving trick), the LCD needs to know what the brightest pixel is and then adjust the whole image so it remains the same while matching the brightnest pixel using the dimmest backlight possible. Tricks like those might explain why the slowest panels on this roundup are almost exactly two frames slower than the fastest: one frame delay to shift the frame in the memory buffer while applying filters and searching for the brightest pixel, another frame delay to shift the frame out to the panel with adjusted brightness.
Many LCDs do a lot more than simply dumping signal straight from the input to the display controller.
I wish threads that got bumped by spammers would stop bouncing back into my "new updates" list every time spam gets added and removed. I must have come back to this thread with the above post as most recent more than a dozen times by now.
I wish the forum would delete "new update" notifications when the newest post in a thread is older than the notification after spam got deleted.