[John Casler]

I should know the answer to this, and I'll probably be doing a  when someone post it but:

I have a 480p projector that will accept 1080p input.  Obviously it then down converts to 480p to project.

I also have an OPPO upconverting DVD player, and a SAMSUNG digital High Definition TV tuner.

Both of these are set to 1080p output.

The interesting thing is that the TV High Def picture is LOADS better than the DVD no matter WHAT resolution I use (480p, 720p, or 1080p) for the DVD output.

I find this interesting and puzzling, and can think of no explanation, but the difference is not subtle on HD Programming. 


All cables are HDMI.

The tuner will adjust to the stations output, and the projector then adjusts automatically.

That is, if the station is 1080p, then you can watch as the projector cycles to 1080p accpetance, and the same with 720p, etc.

Has anyone else seen this?  or know of the reason?

[IronLion]

Wouldn't the HDTV have more source resolution to play with than your OPPO, even though in your case its down converting?  I mean, isn't the OPPO playing standard def DVD's at basically their standard resolution, while with your HDTV it has more information from the start?

[John Casler]

Wouldn't the HDTV have more source resolution to play with than your OPPO, even though in your case its down converting?  I mean, isn't the OPPO playing standard def DVD's at basically their standard resolution, while with your HDTV it has more information from the start?

That might be it.  Maybe I need to try a Blu-ray player.

[ebag4]

I have found this to be true as well.  I am no expert but I believe a lot of it has to do with the HD standards that are in place.  It is my understanding that there is a strict standard for HD that the older NTSC (never twice the same color ) lacked.  Also, remember that the live sports HD broadcast are using HD cameras, so the entire process is produced at a higher standard with regard to color, brightness, contrast, etc. as well as higher resolution.  That's my take on it anyway.

Best,
Ed

[John Casler]

I have found this to be true as well.  I am no expert but I believe a lot of it has to do with the HD standards that are in place.  It is my understanding that there is a strict standard for HD that the older NTSC (never twice the same color ) lacked.  Also, remember that the live sports HD broadcast are using HD cameras, so the entire process is produced at a higher standard with regard to color, brightness, contrast, etc. as well as higher resolution.  That's my take on it anyway.

Best,
Ed

My specific "test" was the New James Bond film compared to "Two and a Half Men" on the HDTV Tuner.

This is also on a 120" screen, so I can certainly see small differences, but this is LARGE!

[superchad]

I think it has to do with a direct signal and not one that is transmitted losing quality and then perhaps compressed losing more quality...........kinda like FM stereo vs CD but not that extreme. I have a HDDVD player (budget Toshiba) and a Lexicon 480P and a 720P Projector and the difference between "HD" DVD and 480P isnt all that spectacular, atleast not by as wide margin as many would leave others to believe. My HD (TW cable) on certain channels is much better than 480P DVD but certain true HD filmed disc's are clearly better than any broadcast or 480P so I suppose it could be a combo of broadcast, compression, equipment used in production.....its a crapshoot. It also could be the scaler in any given persons equipment........some are simply better than others, some beleive the Scaler in Panasonic is a standout so perhaps that blurs the lines.

[ted_b]

John, I'd say it's just a matter of resolution or data to begin with.  Down conversion loses less important data than up conversion can ever find or extrapolate.  Think of it this way: which would sound better, a cd ripped to 320k MP3 or a 128kMP3 upsampled to 320K?  The cd will; it began with more resolution.

[PhilNYC]

Maybe the input is calibrated differently for each input signal type?

[tvyankee]

ted b is on the right track.  the easiest way to see what you are talking about is to do this.  put a hd ch on watch it for a minute then put the same ch on non hd watch it for min then put on a regular ch non hd  that's not produced in hd a you will see that when you start with more info from the start and down-rez it it looks a lot better every time.

[darrenyeats]

Not being into HT I don't have a HD set up. I have an SD plasma screen (852x480 pixels) with an SD terrestrial receiver (called Freeview in the UK - broadcast in 720x576 pixels then scaled to 16:9). Basically it is a European SD set up.

However, I've noticed that since more and more programs are recorded in HD (all of the BBC programmes for e.g.) the SD quality has gone up too.

Think of it as higher quality mastering. It is possible to see the effect of differences at the sub-pixel level, this principle is used in smoothing computer fonts for example. This explains the beneficial effect of HD in general.

Back to your specific question, DVD vs HD downsampled (and both may have the same HD source). In this case the process of squeezing the data onto the much smaller capacity DVD using lossy compression hurts the image quality more than taking the higher quality HD image and down-converting it to the DVD resolution. The down-sampler doesn't have to apply drastic lossy compression to do its job because it's not storing any data. So although the resolution may be the same as the DVD the image is more accurate. Just an educated guess.
Darren

[welwynnick]

DVD is heavily compressed when it is MPEG 2 coded.  That means when you replay it at native resolution, you will be seeing compression artifacts such as codec noise, macro-blocking, image softening and general loss of resolution and quality.  These effects will be especially obvious where there is lots of motion.  Thsi means DVD cannot resolve all the detail in the original 720x480 image.

BD & HD is compressed as well (more if anything, though the codecs are better) and is similarly incapable of resolving all its native 1920x1080 resolution.  However, it is far better at resolving all the detail replayed in an SD display. 

So its all down to resolution loss with compression.

Nick

[darrenyeats]

DVD is heavily compressed when it is MPEG 2 coded.  That means when you replay it at native resolution, you will be seeing compression artifacts such as codec noise, macro-blocking, image softening and general loss of resolution and quality.  These effects will be especially obvious where there is lots of motion.  Thsi means DVD cannot resolve all the detail in the original 720x480 image.

BD & HD is compressed as well (more if anything, though the codecs are better) and is similarly incapable of resolving all its native 1920x1080 resolution.  However, it is far better at resolving all the detail replayed in an SD display. 

So its all down to resolution loss with compression.

Nick

I know what you mean by the word resolution, which you are using in its general sense, but in terms of digitised displays (TVs, computers, phones) "resolution" refers specifically to numbers of pixels. So I would say the compression in DVD affects the accuracy (maybe there's some better term) but not the resolution of the picture.

If you re-read my last post with this in mind it should make sense...we agree on the cause of the problem.
Darren