[opendtv] Re: Well, well, well; five years to match 1999 COFDM indoor antenna performance

From: Craig Birkmaier <craig@xxxxxxxxx>
To: opendtv@xxxxxxxxxxxxx
Date: Thu, 2 Sep 2004 09:32:33 -0400
More catching up...

At 9:52 AM -0400 8/25/04, John Golitsis wrote:
>----- Original Message -----
>From: "Craig Birkmaier" <craig@xxxxxxxxx>
>
>>  Because that the the native resolution of the display. Providing more
>>  resolution in a display of this size is a waste of time and money -
>>  the viewer will not notice the difference at the designed viewing
>>  distance.
>
>So why bother offering HD at all??

Because HD DOES make a difference on larger displays.

This should be obvious to anyone who has sold interlaced RPTV systems 
over the years. As the screen size increases at the same (or nearly 
the same0 viewing distance, you need more display samples to 
accomplish two things:

1. Prevent the perception of the raster and/or the individual samples;
2. To deliver enough detail with adequate contrast to perceive a sharp image.

The driving forced behind the development of HD was the increasing 
size of consumer displays. It is NOT a coincidence that the HD 
viewing experience is defined as covering a larger portion of our 
field of view, at a viewing distance that is significantly less than 
a smaller display, as measured in screen heights.

So to answer your question directly, we must decouple the display 
from the formats that are available to it. The display must do 
whatever is necessary to deliver a sharp picture at the designed 
viewing distance; this is true for ANY format, whether it is SD or 
HD. But the display DOES NOT need to display all of the samples from 
all of the formats; it needs to convert all formats to native display 
resolution.



>  > How about telling them that they will enjoy the highest resolution
>>  pictures possible with their sets. Almost twice the resolution of
>>  SDTV.
>
>Which is what they're getting now.  So again, why bother with HD at all?

NO, that is NOT what they are getting now. There is a HUGE difference 
between a 27 inch interlaced display and a 27 inch progressive scan 
display. With an properly designed EDTV display they will perceive 
the maximum resolution possible for a screen of that size at the 
typical viewing distance. IF you tried to build a 27" display with 
full HD resolution you would significantly increase the cost with 
little,  IF ANY,  improvement in perceived resolution; with CRT 
displays the picture would probably look LESS SHARP.

>I'm not sure how the display's refresh rate relates to it's vertical 
>resolution
>capability, but I believe these sets that *scan* at 100Hz refresh will not
>accept a 100Hz input.  Again though, why bother with HD at all?

Obviously the Europeans felt that they could deliver significantly 
improved image quality by using their current scanning rates while 
delivering digital component video instead of analog composite video. 
And they could do this in a way that is fully compatible with the 
existing analog receiver base (with an affordable set-top box).

I do not know whether the 100Hz sets can accept a 576P input; that is 
a matter for the digital image processing circuitry in the set. But 
the added cost to support 576P is trivial, once you increase the 
scanning rate.

>
>>  The 30" Color Dynaflat I saw at Sears for about $850:
>>
>  >  Sears item #05742084000 Mfr. model #TX-P3075WH
>>
>>
>>
>>  B&H  sells it for $899. The specs claim a maximum of 800 lines
>>  horizontal resolution:
>
>First of all, this display *will* accept an HD input and *will* scan 
>1080 lines.
>Second, how do you know that spec isn't in TVL?  Regardless, I would 
>MUCH rather
>have one of these, than be stuck with an ED-only set.

This IS an ED ONLY set. The display cannot resolve the extra detail 
in an HD signal. Accepting a 1080 line input is NOT the same thing as 
displaying it. What it does internally is a manufacturers decision. 
In most cases the manufacturer will select the best scanning rate for 
the display and convert ALL formats to that scanning rate. In this 
case the display is refreshed at 480P for SD formats and 1080i for HD 
formats.

Regards
Craig
 
 
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[opendtv] Re: Well, well, well; five years to match 1999 COFDM indoor antenna performance

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