Results: Stock Brightness And Contrast
Before calibrating both panels, we measure zero and 100 percent signals at both ends of the brightness control range. This shows us how contrast is affected at the extremes of a monitor's luminance capability. In DoubleSight’s case, we used the contrast control to manipulate the light output.
At over 300 cd/m2, both panels offer more than enough light output for any work environment. The HP was set to maximum brightness while the DoubleSight display had its contrast set to the highest possible value without clipping detail. While you could increase its output to around 375 cd/m2, the image would be so lacking in detail that it wouldn't be usable.
More and more panels today have LED backlights, but these two still use CCFL. Let’s see how that affects the black level.
The HP falls to the middle of the pack, while the DoubleSight fares somewhat worse. It might be said that LED backlighting provides a superior black level, but our results show this is not always true. Both the HP ZR2740w and the Auria EQ276W utilize LEDs.
With both monitors close in max brightness, the black level is what determines the final contrast ratio.
The ZR30w manages to crack the 1000:1 barrier, but the DS-309W is 34 percent lower at 670.9:1. This is a fair result, and it’s still ahead of the Auria. To our eyes, both panels display a decent image with good punch and detail. To put the contrast-winning Samsung on your desk, you’ll pay around the same price and give up 33 percent of your screen area.
To measure the minimum brightness levels, we turned down the HP’s one and only adjustment, brightness control. On the DoubleSight, we left the brightness alone and reduced the contrast to its lowest setting.
The minimum output level of both panels still provides a very usable image. If you like to work or game in a totally darkened room, these screens will allow for a good degree of comfort to the eye. Detail and color saturation are retained as well.
Some of our recently-tested monitors achieve absurdly low black levels when the brightness is reduced.
The ZR30w follows suit by measuring a very black 0.0458 cd/m2. DoubleSight's DS-309W, however, only drops 19 percent to 0.3652 cd/m2. The difference is barely visible to the eye. No matter where the contrast control is set on the DS-309W, the black level is about the same.
Along with low black levels come high contrast ratios. If you like to use your computer in the dark, this can often be the best way to achieve maximum image depth.
The HP’s contrast ratio doubles to 2164.5:1 at the minimum brightness setting. Because of its relatively high black level, the DoubleSight’s number drops to 167.3:1. Even though color and detail are still OK, the image looks washed out at these settings. For best results, we recommend keeping the DS-309W’s output setting above 100 cd/m2.