The HL247DBB has a maximum contrast ratio of 80000000:1. That's over sixteen times the contrast ratio of a 5000000:1 PC screen, which is the most common contrast ratio. The best contrast ratio of all medium monitors that have been on the market for more than a year is 100000000:1 and the worst is Mega Contrast.
It may also be worth considering one of the other PC displays that have an 80000000:1 dynamic contrast ratio currently available including the Asus VN248 (£102.51) which is cheaper; or the VX279Q (£197.39), or the VC279H (£165.58) both from Asus which has a better Rating.
If the contrast ratio of this PC screen is too low for you then you might want to consider the 42HQL (£117.23) (100000000:1 and cheaper), the K212HQL (£86.00) (100000000:1 and cheaper), or the 12HQLB (£88.74) (100000000:1 and cheaper) all from Acer.