Original Link: http://www.anandtech.com/show/7240/monoprice-zerog-slim-27-ips-monitor-review

We’ve almost all bought things from Monoprice -- most likely some cables, maybe printer toner, perhaps some speakers. They certainly come to mind for those products, but until recently you didn’t think of them for monitors. Now they offer a line of 27” and 30” IPS displays that are priced to compete with the imported models from South Korea. Their newest 27” model is also the least expensive: the Zero-G Slim.

The 27” 2560x1440 IPS display sells for only $390, or $386 if you want to order 50+ of them at once. That's more expensive than some import brands, but it does undercut competitors like Nixeus in the budget 27” realm. One way it gets here is by being DVI only. There is a VGA input, but if you want to stay all digital you’ll need to use DVI.

It also features an external power brick. Many people aren’t as bothered by this as I am, but I prefer an IEC connector. The strangest design choice is the on-screen controls. The front of the display is very clean, with a metal finish around the front and a very simple look. To accomplish this all controls have been placed on the back of the screen. There are no labels on the front to guide you. You need to learn the buttons and rely on memory to use the OSD. This isn’t the worst design I’ve used but it isn’t far off. Perhaps most users never adjust anything on their display, but I don’t like to reach around back and fumble around for the power button and other controls.

The OSD has access to basic controls and preset color temperatures. There is a gamma control that is curiously labeled “On/Off” and not with a numeric value. Beyond the basic controls and a one-point adjustable color temperature, there isn’t much you can adjust on the Monoprice.

The flat front look that Monoprice uses looks nice from a distance, but up close and in use the 1” bezel feels very large. The bezel on my monitor next to it is larger, but being raised and not flat causes it to feel smaller. It’s a personal thing but it felt like I was looking at a massive bezel while using it.

The glossy finish of the Zero-G will certainly make some people very happy.  It’s not glass but a laminate in front of the panel that has an anti-glare treatment applied. It isn’t the reflection magnet that some displays are, but it also doesn’t hide them well. In the Brightness and Contrast section, you’ll see what I think they do to deal with the inherent issues of a glossier finish.

With an IPS panel, the viewing angles on the Monoprice leave nothing to worry about. You’ll have a bigger issue with reflections from the screen finish than you will from any colors washing out or having contrast shifts. Those flaws are absent from any normal viewing angle.

The stand attaches easily with two screws at the base but offers almost nothing in the way of adjustments. Tilt is the only thing you can adjust on the Zero-G with the included stand. There are standard 100mm VESA mounts on the back for an after-market stand if you need more flexibility.

Monoprice Zero-G
Video Inputs DVI-DL, Dsub
Panel Type IPS
Pixel Pitch 0.2331mm
Colors 1.07 billion
Brightness 400 cd/m^2 typical
Contrast Ratio 80,000:1 Dynamic
Response Time 6ms GTG
Viewable Size 27"
Resolution 2560x1440
Viewing Angle (H/V) 178/178
Backlight LED
Power Consumption (operation) < 90W
Power Consumption (standby) < 1.5 W
Screen Treatment Anti-Glare
Height-Adjustable No
Tilt Yes
Pivot No
Swivel No
VESA Wall Mounting Yes, 100mm x 100mm
Dimensions w/ Base (WxHxD) 25 5/8" x 19 3/8" x 7 1/4"
Additional Features NA
Limited Warranty 1 Year
Accessories DVI-DL Cable, AC Power Cable
Price $391


The Zero-G is rated for 440 cd/m^2 of brightness, but with the default contrast setting I couldn’t get close to that. I only managed to produce 348 cd/m^2 of brightness with the Brightness at max and Contrast at 50. Pushing the Contrast higher might push that value higher, but it also introduces clipping that makes those settings unusable.

The curious value with the Monoprice is the minimum white level. At the default Contrast setting of 50 and the Brightness at 0, we still see 267 cd/m^2 of light output. That’s over 30% higher than our bright target for calibration and pre-calibration readings! I like to see the minimum level be closer to 80 cd/m^2 or below, so this is a small range. As you see on the chart, the Monoprice really sticks out here.

White Level -  XR Pro, Xrite i1D2 and XR i1DPro

Black level also has issues. With the Brightness at 100 and Contrast at 50, we see a black level of 1.3178 cd/m^2. We really look for a value of 0.300 cd/m^2 or below to be excellent, and past 0.500 cd/m^2 is not great. Beyond 1.0 shows that we have grayish blacks, not black-blacks, and the contrast ratio is going to really suffer.

At the Brightness level of 0, our black level is a more respectable 0.3216 cd/m^2. The minimum brightness levels are what I’d expect to see at maximum brightness on a typical display. As almost everyone is using LG panels in their 27” 1440p monitors, there is something in the electronics of the Monoprice that is certainly strange.

Black Level - XR Pro, Xrite i1D2 and XR i1DPro

The contrast levels, as you can imagine from that maximum brightness reading, are strange. We see a respectable contrast level of 836:1 at minimum brightness, but a maximum brightness contrast of only 272:1. When these values don’t line up with each other, or with the 200 cd/m^2 calibrated values, I go back and run this at multiple levels to see what is going on. Below is the data for the light output and contrast ratio at different brightness levels.

Brightness Level

Light Output (cd/m^2)

Contrast Ratio


































As we see the light output doesn’t really change from 40-70, and past 70 the black level rises causing the contrast ratio to fall. Contrast Ratio should be constant, with small fluctuations due to reading error. Because of the behavior seen here, I chose to do all my calibrations at the default settings of Brightness 50 and Contrast 50. However, there is something going on with the electronics inside the Monoprice display, and it doesn’t look right.

Monoprice looked into this and informed me that the backlight level is controlled by the scaler and not by the pcb mainboard. This is causing the brightness controls to not function as I expect them to, and it sounds like it won't be changed.

Contrast Ratio -  XR Pro, Xrite i1D2 and XR i1DPro

All calibrations are done using CalMAN 5.1.2 software with an i1Pro meter and a C6 meter. Our targets are 200 cd/m^2 and gamma 2.2 for the pre-calibration and post-calibration measurements with the sRGB colorspace. We also try for 80 cd/m^2 and the sRGB gamma curve to see how well a display handles a more demanding professional setting.

  Pre-Calibration Post-Calibration,
200 cd/m^2
80 cd/m^2
White Level (cd/m^2) 325.75 199.38 81.14
Black Level (cd/m^2) 0.373 0.335 0.322
Contrast Ratio 874:1 595:1 252:1
Gamma (Average) 1.309 2.195 3.051
Color Temperature 6744K 6584K 6648K
Grayscale dE2000 7.853 0.589 1.100
Color Checker dE2000 7.611 0.942 1.000
Saturations dE2000 5.413 1.083 0.995

Running the Zero-G at Contrast 50 and Brightness 50 with the sRGB preset, these are the best numbers I could obtain without a calibration. Since we are targeting 200 cd/m^2 and not 325 cd/m^2, that makes the numbers worse since we are expecting it to be 200 cd/m^2.

We see the gamma is incorrect and there are large grayscale errors. If I adjust the Brightness to 0 we see a gamma that is still wrong, and a blue color shift that gives us an average color temp of 8797K. The contrast ratio also falls to 580:1 and overall performance is worse.

If you only look at the Color Gamut chart, everything looks nice. Switch to the Saturations chart and you’ll see that the 40% red saturation target is past even where 60% should be. Blue and Magenta are over-saturated as well. The color checker chart confirms these saturation errors. This is why using only the standard gamut chart, as many people and print magazines do, provides little insight into actual performance.

Out of the box, the Monoprice Zero-G offers weird, strange performance that I haven’t seen in a long time. It also offers proof of why a panel in a monitor is only a small part of what leads to a quality display.

Calibrate the Monoprice and you have a totally different display. Look at the numbers and they are virtually perfect. If you are targeting 200 cd/m^2 you will have trouble doing better except with contrast ratio and black level. Those are still worse than what other monitors can produce.

Calibrate for 80 cd/m^2 and an sRGB target and you’ll see that performance isn’t quite as good as the 200 cd/m^2 target. The reason is the brightness control. Below are images from the CalPC client that CalMAN uses to calibrate. You can see the default line (in black) and the adjustments made to Red, Green and Blue channels for different output levels. Ideally these should track the default line.

On the Monoprice they start out much lower on the right. Because we have to correct for the brightness levels in the LUT, instead of using the display controls, we lose dynamic range and contrast ratio. The black level doesn’t change but the white level is dropping. We also don’t have as much room for adjustment for the gamma curve, which is why the sRGB one suffers.

CalMAN has corrected a lot of the flaws in the Monoprice compared to the default settings, but it has to take a large hit to contrast ratio to do so.

Display Uniformity is measured using CalMAN 5.1.2 at 25 locations on screen. Every measurement is compared to the center reading, which is the reference point.  Here the Zero-G does very well. I expected a far less uniform display than I got.

White level is very even, staying in the 90%-100% range over most of the monitor. Even viewing gradients and full-white test patterns on the screen I don’t notice issues with the uniformity here.

Black level has a larger uniformity issue. The upper-left corner suffers from a fair amount of light bleed. It is more bleed than I have seen from other displays, and is easily noticeable. The other corners are better, though the upper right is also a bit light. The upper-left is easy to notice in daily use.

Because of that bright corner, the contrast uniformity drops in that area. The right side of the display has better contrast than the center due to a lower black level on that half. 

On our color uniformity test, the Monoprice is nearly perfect. The highest dE2000 error compared to center is 2.13, and even that is virtually invisible. Despite its low cost and some backlight issues, color uniformity is nearly perfect on the Zero-G.

I expected to see results that were more similar to the Black Uniformity on the Monoprice Zero-G, but the results on White Uniformity and dE2000 Uniformity are very impressive. I’m really surprised in a good way by these results.

Once again, there isn’t a good lag tester on the market that can do 2560x1440 natively. I’m sticking to using the Leo Bodnar lag tester at 1080p because it is a well-known, reliable test that is easy to duplicate. Most scalers also introduce very little delay now compared to color management and other display features.

Input lag is 22.53ms, which comes in ahead of most 27" displays except for the BenQ that is a native 1920x1080 display. I didn't notice much lag myself, if any, when using the Zero-G. Advanced picture controls like a color management system are more likely to introduce lag than testing at a non-native resolution, but this result still might improve if it were run at 2560x1440 and not 1080p.

Processing Lag Comparison (By FPS)

Power usage on the Monoprice appears a bit strange. As I discussed, the Brightness control does not control the backlight as it should. Because of that, power usage is basically constant from minimum to maximum brightness.

LCD Power Draw (Kill-A-Watt)

Candelas per Watt

The gamut on the Monoprice is 74% of the AdobeRGB gamut, which is slightly more than the sRGB gamut size of 71%. Nothing out of the ordinary here.

LCD Color Quality

The Monoprice Zero-G seems to be clearly aimed at those after a cheap 27” 2560x1440 monitor who don’t care about extras or frills. This market was opened up by Korean imports like the Catleap and now has a number of companies trying to compete with those eBay sellers. Monoprice is entering the fray with the Zero-G, currently available for $391. That's a good price, but what does it get you?

The Zero-G is a bit curious in its results. The out-of-box numbers are really quite bad, and the Brightness control does not function correctly. Outside of a narrow range it simply doesn’t do what it's supposed to do, and adjusting it too much causes a huge loss of contrast ratio as well as even worse gamma. The color accuracy also is very poor out of the box.

Once you calibrate it, the Monoprice puts out a fantastic image. The contrast ratio suffers due to the brightness limitation, but color and grayscale accuracy, as well as gamma, are spot-on. This behavior put the Zero-G into an area that makes it harder to recommend as a good solution for users.

If you need accuracy, you can spend $150-200 more and grab the Dell U2713HM, which is frequently on sale for around $600. You also gain an adjustable stand and multiple inputs instead of just DVI. You could spend the money on calibration gear, but by the time you have an accurate setup (which means software and a spectrometer, not just a colorimeter) you’re well past the price difference between the Monoprice and the Dell.

If you want to go cheap, for almost the same price you can find the Nixeus VUE 27 display for $485. It also has a stand and OSD that are entry-level like the Monoprice, but it has more inputs and better uncalibrated results. If you have a laptop or desktop without DVI output, you’re better off with the Nixeus as the DispayPort input alone will save you from buying a DVI-DL adapter that the Monoprice requires. I’ve seen the Nixeus selling for as little as $400 recently, and at that point the price different is negligible.

If the Monoprice had better out-of-the-box numbers I can see it being a good choice for some people. With its numbers and its lack of non-DVI inputs, that pool of users grows smaller. Factor in the strange rear-mounted controls and the competition it has, and it gets smaller still. Perhaps Monoprice can improve their firmware and get better results but right now the hardware itself doesn’t function as expected. With all the other choices available on the market, it’s hard to recommend the Monoprice Zero-G over another display that can be had for the same price and offers better performance and features.

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