1080i down converted to 720p?

Archived from groups: alt.tv.tech.hdtv (More info?)

Hi,

I've read some info about DLP HD sets. It seems they all down convert a
1080i signal to 720p. Seems like a lot of picture data would be lost in this
conversion. Three of my local stations broadcast at 1080i. I would like to
get a set that keeps the 1080i at 1080i. Will any of the HDTV do that, in
particular the DLP units? Is a 1080p format on the horizon? I don't want to
spend 4k now only to find 6 months later TV's have much better capability.
Does anyone have any comments on the Mitsubishi DLP WD52725.

Thanks

Bob M

Archived from groups: alt.tv.tech.hdtv (More info?)

"Bob M" <r.mos@yahoo.com> wrote in message
news:-vGdnXjBIozG3uvcRVn-3g@adelphia.com...
> Hi,
>
> I've read some info about DLP HD sets. It seems they all down convert
a
> 1080i signal to 720p. Seems like a lot of picture data would be lost in
this
> conversion. Three of my local stations broadcast at 1080i. I would like
to
> get a set that keeps the 1080i at 1080i. Will any of the HDTV do that, in
> particular the DLP units? Is a 1080p format on the horizon? I don't want
to
> spend 4k now only to find 6 months later TV's have much better capability.
> Does anyone have any comments on the Mitsubishi DLP WD52725.
>
> Thanks
>
> Bob M
Plasma, DLP and LCD Projection ALL downconvert because they do not have 1920
X 1080 pixels. In contrast to reg TV where digital is converted to analog
to display and the resolution is dependant on the bandwidth of the video
circuits (easy) and the display characteristics of the tube (difficult...
focus, convergence, and more). In Plasma, DLP and LCD each pixel element is
individually addressed. This makes for a sharper picture but makes higher
resolution EXPENSIVE. Most DLP have 990,000 elements which at horiz,
pixels=990k/720 or 1375. In practice there is an overscan, some of the
pixels vert and horiz are not used to display a picture so I'd guess that
there are 1320 horiz and 750 vert pixels for a display size of 1250X720.

To display true HD you would need 2,000,000+ pixels =1920X1080+overscan.
Think about how many LCD TV's would sell if the price had to be three times
as high (higher the density the harder it is to make a perfect LCD, DLP
mirror assm or whatever). That said as the cost and technology improve
expect to see higher resolution digital TV's.

Archived from groups: alt.tv.tech.hdtv (More info?)

There is NO ATSC standard for 1080/60p only 60i, 24p and 30p


"Richard" <rfeirste at nycap.rr.com> wrote in message
news:10ncis0mc5ijubc@corp.supernews.com...
>
> "Bob M" <r.mos@yahoo.com> wrote in message
> news:-vGdnXjBIozG3uvcRVn-3g@adelphia.com...
>> Hi,
>>
>> I've read some info about DLP HD sets. It seems they all down convert
>> a 1080i signal to 720p. Seems like a lot of picture data would be lost in
>> this conversion. Three of my local stations broadcast at 1080i. I would
>> like to get a set that keeps the 1080i at 1080i. Will any of the HDTV do
>> that, in particular the DLP units? Is a 1080p format on the horizon? I
>> don't want to spend 4k now only to find 6 months later TV's have much
>> better capability. Does anyone have any comments on the Mitsubishi DLP
>> WD52725.
>>
>> Thanks
>>
>> Bob M
> Yes, there are sets that will convert input into a 1080p display.
>
> But it is not a simple math issue. On most of today's displays converting
> from 1080i to 720p (or 788p in the case of Sony's LCD rear projection
> sets) is not a "down conversion". Most of today's displays can't display
> all of the potential horizontal resolution of 1080i, and most broadcasts
> don't provide all of that potential resolution either. It all depends upon
> implementation, and a shoot out on the single issue of resolution is
> misleading since so many video factors are more important (black display,
> shadow detail, lack of artifacts, color accuracy, contrast, etc).
>
> When 1080p24 and 1080p60 displays become common and affordable they will
> look better not just because of the resolution but because every other
> video factor will have been improved by then (perhaps 3 to 5 years).
> Perhaps by then source material will be produced at 2160p60 and down
> converted to 1080i60 and providers will give it enough bandwidth to show
> the difference on your display.
>
> Richard.
>

Archived from groups: alt.tv.tech.hdtv (More info?)

"curmudgeon" <curmudgeon@buzzoff.net> wrote in message
news:igvdd.20156$mn5.12386@bignews5.bellsouth.net...
> There is NO ATSC standard for 1080/60p only 60i, 24p and 30p
>
True enough, but sets can convert 720p or 1080i into 1080p60 for display
purposes. That is being done already.

1080p60 and 24 can and is being used for production work and converts to
720p or 1080i for broadcast. Soon 2160p will be used for production work and
4x digital is already in use for film preservation, etc.

Richard.