Originally posted by: otispunkmeyer
Originally posted by: jasonja
Originally posted by: otispunkmeyer
Originally posted by: Turtle 1
Originally posted by: malG
Originally posted by: jasonja
A 20ms response time equivalent to 50hz. So to answer your question, go look up all the LCD's with 20ms response times (hint, there's an assload of them). Anything with 16ms response times runs up to 60hz. So running above 50hz refresh rate on a 20ms LCD is pointless... you're wasting bandwidth.
You're wrong...if true then why is my Dell 2405FPW (16ms) natively supported refresh rate is 70Hz?
In the article that started this post it clearly states LCD wouldn't be affected. primative CRT'S only
also jasonja is completely wrong....response time is in no way shape or form connected to refresh rate
response time is the time it takes a pixel to change, and well theres no set standard for measuring it so companies will jus post the fastes response they can get.
refresh is simply the number of times the screen is refreshed, nothing to do with pixel response
60hz for all LCD's is fine because LCD's refresh the whole picture at once, and dont do any painting of horizontal lines
How the hell am I wrong ? If the pixel can only change every 20ms and you're refreshing the output to the LCD every 16ms; it's pretty damn obvious that the pixel isn't going to change every 16ms. Internal it's just dropping some of those refreshes on the floor.. thereby wasting bandwidth. So you can refresh the screen as fast as you want to... but the pixels aren't going to update any faster than the response time.
ok
look here and go down to Refresh rate, response time, flicker and motion-blur
Refresh rate is the rate at which the electronics in the monitor addresses (updates) the brightness of the pixels on the screen (typically 60 to 75Hz). For each pixel, an LCD monitor maintains a constant light output from one addressing cycle to the next (sometimes referred to as 'sample-and-hold'), so the display has no refresh-dependent flicker.
There should be no need to set a high refresh rate to avoid flicker on an LCD.
Response time relates to the time taken for the light throughput of a pixel to fully react to a change in its electrically-programmed brightness. The viscosity of the liquid-crystal material means it takes a finite time to reorientate in response to a changed electric field. A second effect (which has a rather more complicated explanation) is that the capacitance of the LC material is affected by the molecule alignment, and so if a step change is brightness is programmed, as the LC realigns the cell voltage changes and the brightness to which it settles is not quite what was programmed. Unless 'overdrive' (which tries to pre-compensate for this effect) is employed, it may take several refreshes before the light output stablises to the correct value. Response rate for dark-to-light is normally different from light-to-dark, and is often slower still between mid-greys. VESA and others define standard ways of measuring response time, but a single figure rarely tells the whole story.
Manufacturers 'response times' rarely tell the whole story.
Unless combined with a strobing backlight, response times much below 16ms are likely to be of only marginal benefit, owing to more-dominant 'sample and hold' effects (see below),
there you go
also a another good link explaining the differences
here
unless of course i may have the wrong end of your stick here. did you mean to say that 20ms = roughly 50Hz, so a pixel can change 50x a second (for one measurement since black to white takes a different amount of time than white to black, and again grey to grey takes a different time too) so theres no point in redrawing the screen above 50hz?
refresh doesnt really matter for LCD anyway, its mearly there because of the analogue outputs that still exist, these work at a frequency. like that link says i think refresh is simply refreshing the brightness. not really the colour