The moral of this story – find out the panel type before you buy that cheap LCD monitor, and avoid TN type at all cost.
I tried out a new 24-inch Dell LCD monitor at work: the model name is S2409W. For some reason I just don’t like it as my eyes hurt. So I switched back to my old 20-inch 2005FPW. While the 2005FPW is smaller in size, it is much more expensive at new than the S2409W. Other than that, nothing else provided by Dell would indicate there’s something wrong with the S2409W. But,
Now I know the reason, thanks to these two wiki pages:
The first page identifies the panel types of various Dell LCD monitors. The S2409W uses the TN type, while the 2005FPW is of the S-IPS type.
The second page explains the difference between these and other LCD panel types. Apparently the TN type is the cheapo type. It stands for Twisted Nematic. It has limited viewing angle and only 6bit true color resolution. Because of the latter reason, it uses a dithering method to simulate true 24bit color used by most modern UI. This dithering method apparently produces bothersome viewing experience to some, myself included. The S-IPS panels are much more expensive and have much better viewing experience. Dell calls these LCD products the Ultrasharp series.
While my lovely 24inch iMac uses the latest greatest of IPS – the H-IPS panel, the 20inch version is being sued for the cheapo TN type panel it uses. H-IPS is the next evolution of S-IPS. From my experience using it, I have no complaints whatsoever. If you want to see the true colors of your family picture, this is the best. In fact, I was pretty shocked to see how much worse my digital pictures looked on the LCD screen of my Dell Latitude laptop – particularly the color range is atrocious.