On Sat, 26 Apr 2003 03:06:29 -0500, John Dyson <fred@dyson.net> wrote:

>Steve McDonald wrote:

>> Rather than up-converting SD video to be shown in HD form, aren't

>> there (or shouldn't there be) some HDTV monitors that will display an SD

>> signal just as it exists with only 480 visible scanning lines being

>> used? Wouldn't this eliminate the SD quality problems that are being

>> discussed?

>What you say is probably true (except, an HDTV display is likely to have

>better focused beam, and therefore, the display would also want to

>increase the size of the scanlines by defocusing the beam.) However,

>I believe that alot of the negative effect when displaying SDTV on

>HDTV sets is gratuitous and misguided screwing around to 'compensate'

>for the lack of detail in typical SDTV material. A 'clean' upconvert

>would certainly be adequate. My STR-165 does do 'upconversion', and

>I wonder if the HDTV that it creates is clean? Someday, I'll probably

>check that also.

In the case of the HDTV display I saw, the normal broadcast

SD was just soft, without the irritating artifacting that

appeared so exaggerated in the HDTV display of my (sharp,

but not-too-artifacted SD D25, as seen on a good,

high-res-for-its-time SD CRT) display (10 year old Panasonic

27", bought during the "resolution wars" of the time - but

it is sharper than other 27s I've seen, and it shows noticeably

more real detail than my 20" Sony Wega...). The

SD broadcast material, though, went through the whole

system, as did the HDTV broadcast and the DVD - but my

D25 was directly "S"-connected to the HDTV projector...

>As you know, even 'normal' good quality SDTVs screw around with the

>video too much already... This had historically been done to

>help mitigate the effects of the chroma filter (try to replace the

>destroyed detail), and also the grotesque over-enhancement (like

>SVM, which is almost a Frankestein-type botch.)

>

>The only artifact that I'd expect from an HDTV upconvert might be

>some motion artifacting (from de-interlacing or somesuch.) Good

>SDTVs should be able to do 5+MHz or better, so the additional

>bandwidth from HDTV shouldn't make a huge amount of difference,

>because DV25 (any DV format) should already be close to being

>maxed out (maybe not totally, however.)

>

>If the HDTV wouldn't grossly over-hype the upconverts, it seems

>like it should look okay.

>

>John

Yes, this was my expectation. I would be happy to see

the SD D25 sitting in the middle of the HDTV screen

area (with "dead" space on all sides of the image), or

to have a good line-doubled 4:3 upconverted version

sitting in the middle-portion of the HDTV 16:9 (better!).

But what I saw was truly ugly - and given the relatively

higher data rate compared with the other sources, quite

surprising. It could very well be that what I saw was

due to a very poor upconversion - and I hope that that

is true...! ;-)

Thanks for your comments.