Since I did not test any other monitors until today, I can't have any comparison charts at the ready. PB287Q uses a WLED backlighting, and measures a peak brightness of 303 candelas per square milimeter. That's more than enough, especially for in-dore use. Of course the screen doesn't actually emit as much light as the gaming TN panel monitor, PG278Q (which I am currently working on), and it most assuredly doesn't match a IPS panel screen.
Monitors don't usually display the same image across their surface, and in order to test said uniformity, I take a look at its luminance. Whilst I work with the review sample, its worth mentioning, the results apply only to the sample itself, and the resulting values might be different for a different product of the same model.
In order to test the variation, I first set the center of the screen at 220cd/m2, and then take 8 other readings in the surrounding regions.
For luminance uniformity, there seems to be a 14.8% variation from the darkest region, at the top-left corner of the screen, and the center. This variation is almost unnoticeable to the naked eye, though the upper left-corner is slightly dimmer than the rest of the screen.
The black level uniformity is not very different either, and though there are some brigt spots in the center and upper-right portions of the screen, the variation is nigh on unnoticeable.
Delta-E is a measure of color difference, or deviation to the refference. Small delta-E values means more accurate colors.
With an average Delta-E of 1.97 and a 96.32% SRGB color gamut, calibrated at 200cd/m2, in Standard Mode, the PB287Q has some insanely good color performance for a TN panel.
However, the contrast ratio isn't exceptional. With a 884.6:1 contrast ratio, it falls under the quoted 1000 to 1. The 0.3362 cd/m2 (uncalibrated, 0.2776 calibrated) black-point is good for for a TN panel, but only average when you look at other variants.
ASUS rates the optimal viewing angles at 170° of vertical range and 160° of horizontal. Testing these figures is quite simple, you just push to (and over) the angle, and note the difference.
The color-shift is visible on all angles, but it's most noticeable on the horizontal axis. However, to see the change, you'd have to either go under the desk, or get glued on to the ceiling.
Since the panel type is not the only variable that actually influences viewing angles, but also backlighting technology, PB287Q seems to have a wider viewing-angle compared to other TN panels. Also, the image doesn't go through any dramatic change (start looking like a film negative), as it does in some (albeit older) TN panel monitors, but instead the image just loses some brightness and detail.
TN panels are quicker than their brethren, and PB287 is no different, with a 1ms gtg rating from ASUS. However, input lag is a very complicated business, since there are many sources that can influence it. Whilst I do not have a 4K ready screen, I did mention that the PG278Q G-Syng gaming monitor is hooked to my machine, and can serve as reference. I also picked up my old Samsung SyncMaster 2433 (5ms latency) and compared both screens to it. The thing is, PB287 uses the 4K ready ASIC scaler which should also cause some input lag.
Using the screens in Cloning Mode, adding a timer and taking some shots should tell show some the difference between the two screens. I would have liked to add an IPS screen to the test, but we work with what we have.
Overall, the PG278Q is faster, which is to be expected since it's a G-Sync enabled gaming monitor, but PB287Q manages to keep up, being only 11ms behind, which is less than single frame at 60Hz (16ms).
The monitor eats up 5watts in idle, 19watts in minimum usage, and 46 in extreme conditions. Day to day, it averages at around 31watts.