The HP V221 has a maximum contrast ratio of 1000000:1. That's 80% less contrast ratio than a 5000000:1 flatpanel monitor, which is the most frequently found contrast ratio. The contrast ratio of all PC screens of a comparable type and age to the V221 ranges from Mega Contrast to 100000000:1.
We think you might also be interested in some of the other flatpanel monitors that have a 1000000:1 dynamic contrast ratio currently available including because of it's better review score, the LG 34UC97 (£471.00).
Flatpanel monitors with a higher contrast ratio that might also be worth looking at include the P2715Q (£299.99) (2000000:1), or the U2715H (£365.36) (2000000:1) both from DELL which also has a higher Rating.