Upscaling and Downscaling question...


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Aug 10, 2019
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With reference to the Panasonic PX series plasmas which have a pixel resolution of 1366 X 768 I've just read the following about signal acceptance:

"I have found it best to feed 1080P from HD-DVD and 1080I from sky-HD. In my opinion this produces a slightly better picture.

There is also an argument that this approach also results in less scaling of the image, as the processing in the PX70 will upscale an incoming signal to 1080P and then downscale to the native resolution of the panel for display.


1080P->1080P->768P only scales once
1080I->1080P->768P deinterlaces once and scales once
720P->1080P->768P scales twice etc etc

Is this correct about scaling twice - going up and then down [because of the included 1080p chip]?



That does seem to be the case. I definitely remember reading that this range "upscales all incoming signals to 1080p". This might seem odd, but who are we to question this tv's mysterious workings when it does such a good job? Might it be the case that the credit to this tv's superior performance lies with it's seemingly strange methods? ie the process of upscaling to 1080p only to have to then downscale again.

I believe that it all depends on the quality of the source, and it's effectiveness at scaling. For example, if you were using a really high-end upscaling DVD player with HQV, such as Denon's top of the range DVD player (don't know what model number), then you might want to have it set to output 1080p, in order to have the Panny do as little scaling as possible. However, if you had a lesser DVD player then you may want to set it to output at a lower resolution and let the Panny loose ie upscale to 1080p then back down to 768p.

What really matters is what gives what you think are the best results, so try changing the settings and see for yourself which impresses you most.