The highest contrast ratio of the HP 22es is 1000000:1. That's 99% less contrast ratio than the most frequently found dynamic contrast ratio of 100000000:1. The worst contrast ratio of all medium monitors that are a similar age to the 22es is Mega Contrast and the best is 100000000:1.
We compared all the other flatpanel monitors that have a 1000000:1 dynamic contrast ratio to this PC monitor and we think cheaper PC screens such as the V7 L215DS-2E (£79.19) is also worth considering.
If the contrast ratio of this PC display is too low for you then you might want to consider the P2314H (£138.91) (2000000:1), or the P2217 (£99.00) (4000000:1) both from DELL which is also cheaper.