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Thread ID: 88746	2008-04-08 02:56:00	Best device for High-Definition	Chilling_Silence (9)	Press F1

Post ID	Timestamp	Content	User
656906	2008-04-09 00:11:00	Im sure that some can. When I was working for IDG back in the day there was some 23" CRTs (HUGE buggers...) and they could do some insanely high res that the graphic designers used. Not sure on exact specs though, but a quick Google should show that some can :)	Chilling_Silence (9)
656907	2008-04-10 05:17:00	Perhaps I can put my 2 cents worth in. The new Zealand Standard for the PAL system we have is transmitted at 25 frames per second. Each Frame is scanned twice to give a 50 cycle flicker rate. The motion Picture industry show all films on the screen at 24 frames per second. However a dual bladed shutter in the projector shows each frame twice thus making the flicker rate 48 cycles. In New Zealand PAL 625 line system, the film which was shot 24 frames per second, is simply speeded up to 25 frame per second. The reason is Historical in as much our Main frequency is 50 Hertz (cycles per second) and early TV stations used to use the mains frequency to lock their synchronizing pulses to and hence we got a 25 frame 50 field rate. The scanning method used is called inerlaced scanning. As each frame is scanned twice, it is broken into the two fields. Field one scanes lines 1, then 3 then 5 etc and at the end of the scan, the spot flys back (hence the term flyback) to the top of the picture then begins to scan all of the even lines. ie lines 2, 4, 6, 8 etc. At the end of the two fields, one complete frame has been scanned. Now while it is a 625 line TV system, in New Zealand, 50 of those lines are used for what is known as blanking and contain all manner of signals such as sync pulses and teletext information. That leaves 575 lines left for picture. In fact, the maximum real resolution you can get from a Digital picture as transmitted from Freeview Satellite or from Terestrial Analogue transmitters is 575 pixels and that is all you can get from a standard TV signal digital or analogue. Hi Definition pictures are different and use a different method of obtaining a better and clearer image and higher definition. Also, there are two types of image displays. Ther is 1080i which is an interlaced picture, usualy with a 100 hertz flicker rate and the 1080p which is a progressive scan. The interlaced one is the same as for the analogue one except that instead of there being 576 lines, all told, there are 1080 lines. I am unsure if any are used for blanking in that HD system. However the interlaced picture is at a 100 HZ flicker or field rate. Remember the film has to be shown into the telecine machine (for dubbing film to TV recorders) at the film frame rate of 24 or 25 FPS (frames per second). This is translated to whatever frame/filed rate necessary to display the picture at the desired rate on the panel. CRT receivers do have 100Hert'z technology too of course as invented by Philips some years ago. Now the americans use 60Hertz for their mains supply and historically their TV system used their mains for sync generation too. and so they got left with TV sets that run at 30 frames per second and a field rate of 60 fields. To do that a special projector was needed to show one frame twice and the next frame three times then teice so they could build up the frame rate from the 24 of the film to 30 of the TV system. It sort of worked. But with LCDs, they still have to convert it to the new frame rate but using frame stores and memory chips, they can do it easily. The film is still projected at 24 frames per second if the show is originating from film but in America, they are able to use something called Progressive scanning. This is where each frame is scanned in sequence of line 1,2,3,4 and so on to the full frame. ie. It is not interlaced and hence a 1080p HD display is denoting that it is a progressive scan. There are other considerations too when playing from DVD. Standard DVD players still only produce a maximum line rate of 576 in our PAL system. Blue ray 1080 lines. The line rate for HD from TVNZ High Def is 720. I don't know if they are doing it as 720p or 720 i or allowing the receiver to sus out which as most HD receivers can display either. That is the basics of it all, the detail might differ a little. Hope this helps, John	riscpc (5756)
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