Article: Sexy LCD 17"

IceCanuck

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Apr 11, 2002
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Ok, just a quick question. How do these monitors compare to the almighty Samsung Synchmaster 170T? Based on what I've been told and the reviews I've read, the 170T is the best 17" monitor out there in terms of picture quality and responce time. I'm assuming that the 170T was not included in this review because it is an older model? Or maybe it will show up in part II of the review?
 

blexxun

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Apr 5, 2002
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a louzy test..i think they just don't understand how LCD displays work.
The statement "Reminder number one: the eye perceives motion to be continuous starting at 25 images a second." is wrong when applied to LCD displays.
Even for an ideal LCD display with 0 (zero!) response time driven at a vertical frequency of lets say 60Hz or 70Hz significant motion blur would be visible! So, it is wrong to say:
"If the figures given by ViewSonic are correct, we ought to have the same ease of use with games on an LCD as we get on a CRT."
The reason is that LCD monitors are 'sample-and-hold' displays, i.e. a pixel remains on unil it is turned off. This is different for CRTs where a pixel 'flashes' i.e. after it is turned on it goes off immediately ..there is no need to turn it off.

It is important to understand this difference. In fact, LCDs must be driven at a much higher vertical frequency (a couple of hundred hertz)to achieve the same amount of sharpness for moving pictures compared to CRTs. The response time for a CRT is extremely short, about 50us.

Of course, the fact that a LCD display has a resonse time which is not zero adds some extra 'motion blur'.
It is only this extra part which is removed when going down to a response time of 16ms or so.
The only benefit I see when we get the new improved displays is the fact that the gray response will become better which is now in the order of 80..100ms for the best ones. Reducing the gray response down to 25ms would be a big step for gamers. For me, thats not so important.
I only need a fast 'high contrast' response, and thus decided for a Samsung (PVA) monitor 171P. Very fast for B/W but slow for small gray level changes, i.e. dark gray to black. For text reading fast b/w response is important. Combined with Windows XP ClearType this is perfect.

Measuring the gray response by visual perception is relatively easy if you have the right tool. I use a 'gradient bar' moving on a black or white background. This test tells a lot about gray response.
So far I've compared Samsung 171P and Philips 150B2 and 181AS (2years old). The result confirms what Ive already said in my posting about TN vs IPS vs MVA response time.

Talking about response time...actually, all manufacturers measure the response time in the same way: the time delay of the optical response when switching from black to white and vice versa measured at 10/90 % levels. Problem is, thats not the whole story. What also counts especially for gaming (I guess) is gray response.
Very confusing is the fact, that in some monitor data sheets only the on **or** off time is specified. You can be sure the Viewsonic VG700 will only have an **on** response time of 16ms but not for the total. Their panels are obviously coming from Chi Mei and so far I haven't seen anything fast from them. Additionally, Viewsonic is definitely not high end..thats NEC/Samsung/Hitachi/Philips/IBM/Fujitsu....but Chi Mei? Never. Maybe they do something based on cross licensing...who knows--their home page doesnt give any clue.

Then I read in the review that the Solarism display has an IPS Samsung panel. Thats interesting because IPS is proprietary to Hitachi (maybe NEC/Mitsubishi as well). Samsung uses only TN/MVA and their own invention "PVA" but certainly not IPS.

Also the test is not consistent to what they've written before. Didnt they send MVA to hell before?
 

blexxun

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I was wrong wrt Chi Mei....NEC and Chi Mei are working together and ChiMei has already used Mitsubishi’s FFD in a prototype...ok ok
I'm actually wondering which panels in Eizos L356 & L565 are...They feature 6/19ms=25ms for the 365 and on THG it is listed as a TN panel...so it has FFD then? How, come that a TN panel is that "fast"?