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Discussion Starter · #1 ·
Most DTV tuners will sideconvert 720p to 1080i, as very few HDTV Monitors do native 720p display.


Unfortunately the older Panasonic models, TU-DST50 & 51, give you three choices for 720p, but none of them sideconvert to 1080i.


You can choose to downconvert to NTSC, downconvert to 480p or run native 720p.


Sorry for the bad news.


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Ouch.


What do you mean by "sideconvert" by the way?


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Mike Kobb

(Formerly "ReplayMike", but no longer affiliated with the company; these opinions are mine alone.)
 

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Discussion Starter · #3 ·
Since both 1080i & 720p are HDTV formats, and both contain comparable (not identical) amounts of picture information, I've coined the term sideconversion (as opposed to up or down conversion) to describe the process when going from one to the other.


Vic Ruiz recently posted the following re: 1080i & 720p: 1080i has "Just 12.5% more pixels every 1/60th of a second. It's only an optical illusion that makes 1080i look sharper. The actual difference is only 12.5%."


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[This message has been edited by Ken H (edited 09-03-2001).]
 

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Ah, thanks. So, maybe this answers one of my questions. The Mitsubishi DLP set contains an element whose native resolution is 720p, precisely. And yet, the set only takes 1080i input. So, I wondered how much artifacting would be caused by converting from a 720p broadcast to 1080i in the set-top, then back to 720p for the element...


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Mike Kobb

(Formerly "ReplayMike", but no longer affiliated with the company; these opinions are mine alone.)
 

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i have a panasonic TU-DST50 decoder with a mitsubishi set that doesn't accept 720p. My question is what happens with a 720p signal such as abc material? Does it upconvert to 1080i? or downconvert to 480p? I have it switched to 1080i and 480p only. my experience last night with the brady sequel is that it downconverted to 480p...looking bad. any way to upconvert?



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Am uncertain. If your projector can handle both 720p

and 1080i, which would provide the better image from the

E*6000 HD setting?
 

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Quote:
Originally posted by hmars:
Am uncertain. If your projector can handle both 720p

and 1080i, which would provide the better image from the

E*6000 HD setting?
My experience with the 6000 has been that 720P (ABC on Expressvu) has looked better in the 720P format while 1080I looks better in 1080I. Converting one to the other seems to introduce noticeable degradation.

 

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Discussion Starter · #8 ·
As cwood says, use native formats with displays that are compatible. In other words, don't up/down/side convert, if at all possible.


Unfortunately, this is not always the case. Most consumer direct view & rp TV's don't do 720p. This makes the sideconversion mentioned above the next best thing, and on many displays you can't tell anyway, as they don't have enough resolution to let you see the difference.


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cwood, thanks. To summerize, if SHO broadcasts 720p

then set the 6000 to 720p. For HBO 1080i, set to 1080i.

Otherwise, from other threads, it would appear 1080i

resolution is superior.
 

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I am questioning the statement that 1080i has only 12% more pixles per second than 720p. The 720p format is capable of 60 frames per second (fps) progressive. However, all HD cams that I have seen for sale are either 720p/24 or 1080p/24. So the 720p signal received actually has half of the pixles of a 1080i signal since it only has 24 fps. Are there any HD cams that work at 720p/60?


This brings up another interesting point. Since all 1080i pictures originate as 1080p/24 why is it always broadcast in 1080i? I heard a rumor on another thread that CBS was considering switching to 1080p.


Rick R

 
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