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I noticed that some DVD's (including the Superbit Fifth Element) have black bars at the top and bottom when displayed on my Panasonic plasma. Switching to Zoom mode gets rid of the bars, but the images are stretched vertically. What's going on? Anyway to correct this?
 

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You have a 1.78:1 display (16x9). Some movies are shot in that aspect ratio. Others are shot in 1.85:1 or 2.35:1 (and I think there's even a 2.55:1) ratio, that are even wider widescreen. So in that case you'll have black bars on the top and bottom or you can zoom it like you did, which I didn't think usually stretched anything, but does crop off some of the sides of the picture.


If you were watching one of those 2.35:1 movies on a regular 1.33:1 TV, those black bars would be HUGE. I watched LOTR on my 36" tube before we got a front projector, and the bars took up 40% of the screen.
 

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I hope this helps somewhat………..


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A DVD video can only be encoded in 4:3 format

- 480 X 720 (rectangular pixels)


Yet most movies are shot in widescreen ( ie 16:9 or whatever)

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So in order to encode movies onto DVD’s they have to convert the signal into 4:3 and then encode it onto the disc.


So if you want to encode the movie without cropping or panscan it leaves you with the two following options:


1) Letterbox : compress the picture vertically and horizontally and then add black bars on top and bottom to get a 4:3 signal from a 16:9. Then encode it onto DVD.

- this means the bars are part of the signal and the movie is widescreen albeit at a lower definition

- on a 4:3 tv you will see a full 4:3 signal which includes bars on top and bottom

- on a 16:9 tv you will see bars on all four sides but only the top and bottom are actually signal. You must zoom in to get full screen


2) Widescreen / Enhanced Widescreen / Anamorphic Widescreen : the original widescreen film is horizontally compressed (ie – from 16:9 to 4:3 would mean the horizontal is compressed by 33%). It is then encoded onto the DVD in this squished 4:3 format.

- a 4:3 tv will show the signal in full screen but everything will be tall and skinny. To fix this the signal must be vertically squished to give black bars on the top and bottom. This gives you the identical picture as “letterbox†does but the black bars are not encoded on the disc.

- a 16:9 tv will stretch the signal horizontally to get full 16:9 screen.


Contrary to popular belief an anamorphic signal does not maintain the full resolution of the original movie. There is still some horizontal resolution loss. You cannot compress and decompress without some loss. The greatest benefit to anamorphic is that you maintain the vertical resolution of 480 lines per frame (well at least people with 16:9 tv’s do)
 
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