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Thread ID: 73900	2006-11-05 03:23:00	De-Interlacing?	SurferJoe46 (51)	Press F1

Post ID	Timestamp	Content	User
496517	2006-11-05 03:23:00	Can anyone tell me what De-Interlacing is? I see it as an option in WMP and wonder if I should turn it on or off. What's the good or bad of it?	SurferJoe46 (51)
496518	2006-11-05 03:38:00	You might find some useful info here (en.wikipedia.org). The essence of it seems to be: "When displaying video on a display that can support a high enough refresh rate such that flicker isn't perceivable, interlaced video can be deinterlaced for better viewing."	Greg (193)
496519	2006-11-05 04:11:00	I see that de-interlacing is just not for CRT's: All current displays except for CRT screens require deinterlace . Though in principle there is no reason why LCD, DLP or Plasma displays should not display two fields sequentially, the requirement that half of the pixels remain black would result in a halving of brightness, even assuming that the response time of the technology could be made fast enough . I see that my CRT displays should have de-interlacing turned off . . . . :waughh: I see that LCD's and their ilk will halve their brightness if the alternate lines are black . . . as black is a FULL ON signal to them, just the opposite of CRT's; black for them is ALL OFF .	SurferJoe46 (51)
496520	2006-11-05 09:13:00	I see that LCD's and their ilk will halve their brightness if the alternate lines are black . . . as black is a FULL ON signal to them, just the opposite of CRT's; black for them is ALL OFF . I can't agree with that logic SJ . Interlacing was intended to minimise flicker on CRT TV screens running at 50 or 60 HZ . It is redundant for most modern video refresh rates . However, looking at your statement above I can't agree because "black" on a CRT screen and "black" on an LCD screen are both created by turning the video drive off . They are an absence of light output . In fact, if black was the "full on" signal with an LCD screen, the thing would light up like a searchlight when there was no drive present, which defies logic . The beam current in a crt is driven "on" to excite the phosphor triads on the back of the faceplate and thus create screen illumination, while the liquid crystals on an LCD are "untwisted" or driven "on" to effectively do the same thing by allowing the backlight to shine through . There is actually quite a bit more to it than that for LCD screens but I'm just keeping it simple . As an aside, the blackest any screen type can ever get is how it looks when switched off . Black is just an illusion created by the contrast between the lit areas and the unlit areas . Have you ever considered how a white screen at the movies can show "black"? It is purely contrast that creates that effect, which is partly why movies are shown in darkened theatres, the other reasons are atmosphere and to minimise the projection power needed . I am amused by the huge "contrast ratios" quoted for some plasma and LCD screens . That is more a measure of how bright it can be driven(or overdriven), and you might not want to watch it under those test conditions . Cheers Billy 8-{)	Billy T (70)
496521	2006-11-05 15:49:00	Hm.. I wondered about that...but Dell LCD's come with the warning to turn them off as the black screen that shows when the puter is off but the screen is on causes premature failure by high saturation trying to achieve a black screen with no vid signal. That sounds like a "Full-on" condition...No? Without a signal from the vid driver, then the LCD screen assumes by default, pure as possible black, and the screens actually get a little warm after a while.	SurferJoe46 (51)
496522	2006-11-06 01:44:00	Well, the actual LCD is voltage driven, not current so there's no heating there, but if the backlight stayed on then there could be a heat buildup. In any event, the black screen is created by removing the voltage from the LCD matrix so that the crystals "untwist" and stop passing light so it all sounds like a manual writer's corruption of an original instruction from an engineer. Remember what I said in my previous post, there is no "black" and the screen can't be driven to produce black. Unplugging the monitor will give you the blackest screen possible, which is a pale grey-green, and contrast between lit areas and unlit does the rest. It is an optical illusion, all done with curtains and mirrors and a beautiful, scantily-clad assistant with legs up to her armpits and ginormous gazoombas to distract you from reality. :D Cheers Billy 8-{)	Billy T (70)
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