How can I increase the contrast of my new monitor?

I just got a new LED 16:9 1080p monitor that has a reported contrast ratio of "1000:1 / 100000000:1 (dynamic)". My previous monitor is an LCD that is 1280x1024, with a contrast ratio of 700:1, according to the manual. Yet the new monitor (I am using them side-by-side) has a much lower contrast in reality (picture, new on right). Why would this be? Is it a monitor setting that I can change? Does it have to do with VGA vs DVI vs HDMI?

I'm considering returning the new monitor, but I need to know what to look for when replacing it.