Results: Viewing Angle And Uniformity
Built around an LG-made AH-IPS panel, the PXL2790MW should give us comparable off-axis viewing performance to other IPS panels we’ve tested. We wondered if the layer bonding technology used by Planar might affect the results.
While there is very little light falloff, you can see a slight color shift towards red and green in the side-angle photos. Since all of the light coming from an LCD panel is polarized, the various color wavelengths shift differently as the eye moves from the polarizing grid’s axis. On this monitor, not only is the LCD bonded directly to the front protective layer, but a chemical anti-glare coating is applied as well. This coating has optical properties that contribute to the PXL2790MW’s superb clarity and crispness, but exact a slight cost in off-axis image quality.
Screen Uniformity: Luminance
To measure screen uniformity, zero percent and 100 percent full-field patterns are used, and nine points are sampled. In a change from previous reviews, we’re now comparing the results to other monitors we’ve measured. First, we establish a baseline measurement at the center of each screen. Then the surrounding eight points are measured and their values expressed as a percentage of the baseline, either above or below. This number gets averaged. It is important to remember that we only test the review sample each vendor submits. Other examples of the same monitor can measure differently in this metric.
First up is black field uniformity.
This is the PXL2790MW’s only real flaw, and we believe it’s a result of the bonding process used to eliminate the air gap between the LCD and front panel layers. The hot spots are most visible in the upper left, followed by the center and lower left. The lower-right corner also runs slightly brighter than the rest of the screen.
Here’s the white field measurement.
At the other end of the brightness scale, the Planar measures almost perfectly. Such a low uniformity error is pretty much invisible. In fact, it’s the third-best result we’ve recorded this year.
Screen Uniformity: Color
To measure color uniformity, we display an 80-percent white field and measure the Delta E error of the same nine points on the screen. Then we simply subtract the lowest value from the highest to arrive at the result. A smaller number means a display is more uniform. Any value below three means that variation is invisible to the naked eye.
The PXL2790MW’s performance here is even better than its white field luminance test. A .17 Delta E variation is completely undetectable to the eye. It’s almost as small as our i1Pro’s measurement tolerance. The layer bonding process seems to have a positive effect in this test case.
