The Compaq L2311 has a maximum contrast ratio of 1000000:1. That's 95% less contrast ratio than a 20000000:1 PC monitor, which is the most common contrast ratio. The worst contrast ratio of all comparable spec PC displays that were released around the same time as the Compaq L2311 is Mega Contrast and the best is 100000000:1.
It may also be worth also looking at one of the alternative PC monitors that have a 1000000:1 dynamic contrast ratio currently available including the HP ZR2330w which has a better Rating.
If the contrast ratio of this HP LCD screen is too low for you then you might want to look at the P2213 ($99.99) (2000000:1 and higher rated), or the U2412M ($199.00) (2000000:1 and higher rated) both from DELL or the Philips 231P4 (2000000:1 and higher rated).