Out Of Box LCD Performance: Maximum And Minimum Brightness
There are many ways to calculate contrast ratios, which is why you should be wary of any specification that you read on a product page. Oftentimes, manufacturers take the maximum white obtained at the highest brightness setting, and divide it by the smallest black value obtained at the lowest brightness setting. Unfortunately, this doesn't give you a real-world view of a monitor's capabilities.
Our contrast ratios are generated from the black and white luminance values obtained at the same brightness setting. The results mirror our earlier default values because these are uncalibrated measurements. However, this should give you an idea of how bright of a white and how dark of a black a monitor is capable of reproducing.
Notice that neither all-in-one PC can achieve its advertised 300 cd/m2 out of the box. As a result, there's no way either can get a contrast ratio greater than 800:1. The contrast ratio of HP's TouchSmart 310 is the most unsettling; we can't even get a contrast ratio better than 600:1 when we max out the OSD's brightness setting. In an uncalibrated state, the 310 simply cannot generate deep blacks.