There is some misinformation on this thread, and I would like to clear it up for anyone who will be buying a monitor/HDTV.
What exactly does contrast ratio do? The Acer monitor 80108 mentioned has a contrast ratio of 20000:1 and the HP has a ratio of 1000:1, how big of a difference would there be between the two?
The contrast ratio measures the ratio of the whitest white and the blackest black that the panel can display. A larger contrast ratio will result in more vibrant colors, and will generally look better when compared to another panel side by side.
The 20,000 ratio is the dynamic ration not the actual ratio. Pretty much these days LCDs have evolved enough not to look at those things unless you do professional work on monitors. The acer probably has a lower dynamic ration, HP usually has a ratio of 30,000 unless they are above 25 ".
This is sorta true. The ratio of 20,000:1 is a dynamic contrast ratio. It isn't that you don't want to be concerned with dynamic contrast ratio, it's that you need to understand the difference between dynamic and static contrast ratios.
The static contrast ratio is the difference between the whitest white and blackest black that the set can display
in the same frame. You would measure this by hitting pause.
The dynamic contrast ratio is the same difference measured over time. Imagine keeping the meter running and taking whatever the highest numbers where over an entire movie.
As you can imagine, this produces different numbers, that can be misleading when shopping for panels. A high dynamic contrast ratio is preferable for prolonged scenes that take place in dark settings or black and white movies in general. A static contrast ratio offers superior performance when there are sudden transitions from a well lit atmosphere to a darker one, and vise versa.
Unfortunately for you, most manufacturers only give you one of the two numbers, so it's hard to shop between two models. I have a 800:1 28" monitor, and I think it looks great. At your budget, I wouldn't worry too much about the contrast ratio, as you will be fairly pigeon-holed by the money aspect.