Refreshing rate on LCDs... + rip off

[j@cko]

I noticed that LCDs' refresh rate are not very high contrary to CRTs. Wouldn't that cause LCDs to put a considerable amount of stress on veiwers' eyes?

 

[Mem]

Hmmm no,LCDs don`t refresh like CRTs ,the pixels are either on or off, just leave it at the default 60Hz setting.

 

[j@cko]

ic.... thx..

 

[j@cko]

OMG... Dell Canada wants to charge me $1549(CDN) + TAX (15%) = $1782 (CDN) = ~$1300USD for the 2001FP... insane...

 

[WobbleWobble]

Dell Canada also has 10-15% off Software and Peripherals promos from time to time.

 

[JustAnAverageGuy]

ouch on the tax.

 

[0roo0roo]

refresh is opposite in ways. all lcds pixels are drawn at once, and stay on duration. 1hz would be flicker free, cept youd have 1 frame of animation per second which would suck. crts draw the screen line by line, pixel by pixel desperatly fast, while the passed over pixels fade waiting for a refresh. lcds don't list much past 60hz because their pixels have the problem of not being responsive enough to truely refresh 60times a second to begin with.

 

[corkyg]

0roo0roo is on target. Practically speaking, LCDs have no refresh rate. They display staring pixels illuminated by a backlight. Response time is their usual Achilles heel, but that only applies to gamers in most cases - and it is getting better.

 

[NightCrawler]

Well let's define it even more:

CRT's work by drawing using an electron gun one pixel at a time. The Phosphur stays lit long enough for the gun to hit it agian before it dims to much. This is why there may be some eye strain for some people.

LCD's use a backlight and each pixel operates independantly so they all refresh at the same time so there is a lot less eye strain or some would argue.

 

[NokiaDude]

LCD's suck at gaming. I notice with LCD's that when gaming, you get a slight ghosting effect that is annoying. On a nice CRT, there is no ghosting at all.

 

[Mem]

LCD technical info below.

Light is polarized. That is, it has components which oscillate up and down and left and right. There are materials which can only allow certain polarizations through them. Polarized lenses on sunglasses help to reduce glare by not allowing the polarizations that come from reflections through but allowing other light through.

Because all light can be broken down into two perpendicular polarizations, two types of polarizing film can be used to block out all light. That is, if you take two pairs of polarized sunglasses and rotate them so that the lens of one is over top of the lens of the other and the glasses are at right angles to each other, no light should come through the combination of the two lenses. The first lens will block out light in one polarization and the second lens will block out the rest.

An LCD depends on this sort of blocking.

In an LCD, there are two polarizing films arranged in a very similar manner as what I just described, so that no light can pass through them. A special type of material -- a "liquid crystal" which has a certain structure but can tend to "unwind" in the presence of heat or electricity is placed in between them. This crystal's structure twists and, as it twists, can cause light of one polarization to twist with it.

As a consequence, if the two films are placed exactly the right distance away from each other with the liquid crystal between them, light will pass through the first film, get polarized, and will then twist down the liquid crystal until it is perpendicular to its original polarization and will pass through the second film. Thus, because of the liquid crystal, light WILL pass through this arrangement, however it will be polarized on the other end (this is one of the reasons for the way LCDs look -- the particular quality of the image, especially when looked upon at certain angles).

Now, what allows a computer or some other controller to actually make a display out of this is that those liquid crystals can actually be manipulated by electricity to "straighten out." By applying an electric current to the liquid crystal, it will stop twisting the light. As a consequence, light at that point will once again get blocked by the combination of the two polarized films.

A matrix of these LCD pixels can be built and each pixel can be turned on (causing a black lack of light) or turned off (causing light to pass through) in such a way that allows images to be displayed.

Other arrangements of film, crystal, and film can also be used to cause an inverse effect -- so that when electricity is not applied, no light can pass through. Similarly, the light that sits behind each pixel can be a different color. By putting a red pixel, a green pixel, and a blue pixel in close proximity, colors can be formed.

LCD technology is constantly evolving. These are just the basics of what makes it work. Different liquid crystals are being used to create different LCD materials, and different types of control are being used to create different types of LCD displays. It can be very complicated, but all of these new technologies depend on a liquid crystal which can bend and unbend light and polarization films which can block out light

Link .
For gaming fast response time is important in FPS type games,however it does depend on the user and how much ghosting(blurring) he sees,basically
response time determines how fast the pixels change from black to white to black ,however the grey to grey response time is the important one which`s not listed by the manufacturers, in general the lower the response figure the better, but remember in the real world it`s not always the case with some models.