"... And mikeny, are you sure that screen you were looking at was 7000:1? That is impossibly high for lcd. The highest I've seen was 2000:1..."
Contrast Ratio claims of "2000:1" and the like are just BALLOON JUICE. "Creative marketing" [read, DECEPTION] as non-informed buyers perceive that the higher the CR, the better. (Actually, IF it were true, it WOULD be better.)
[The way they get to claim "whatever" in CR goes something like this...
1. The EFFECTIVE CR would be "usable brightness/darkest dark" on the same image. In most cases, that would be only about 120nits/0.6nits, or 200:1, so nothing to brag about.
2. The MAXIMUM STATIC CR would be "brightest possible bright/darkest dark" on the same image. That could be 300nits/0.6 nits = 500. But it would be soooo bright, you'd have to put on sunglasses to view it for very long.
3. DYNAMIC CR is more deceptive.... "brightest bright on ANY image/darkest dark on any image".... not both on the same image. Duh!
4. Then, to bump the CR further, they claim... "if we could cut the backlight power by 50%, we could claim DOUBLE the CR"... and if we could cut it by ANOTHER 50%, we could claim QUADRUPLE the CR"....
The whole business of pumping up the CR numbers is really quite skanky.]
In reality.... ambient light GREATLY affects the CR you will actually see. Unless you run your monitor in a darkened closet, you're unlikely to experience even 500:1 CR.