Originally posted by ADGrant
Couldn't diagree more. It needed to be fixed.
Watching ABC from an external STB would involve a 720p->1080i->768p conversion instead of a 720p->768p conversion. The latter is simply a matter of uprezzing the image, the former involves interlacing, uprezzing, deinterlacing and downrezzing. Not only that, some of the processing will have to take place in the external STB which (if it is a cable box) may not be very good at it.
The only point of my initial comment was to suggest Panasonic may have had a valid reason for their choice. I'm not trying to engage in a heavy debate and they certainly don't need me to defend them. However, before the 50 series they did not seem prone to cutting corners on anything important.
As a purist at heart, I agree in principle with everything you say, I'm just not sure it's as straight forward as that. There is a lot of internal signal processing in these sets and it seems feasible that it may be more efficient to produce a circuit that does it all in in one realm, so the multiple conversions we'd like to avoid may be going on anyway. Some manufacturers' brochures even make a feature out of converting all signals to 1080 prior to processing.
Anyway, page 13 of PD50U manual mentions 720p as part of its STB/DVD capability (as well as 480i which was not listed in the PD25U manual either), then adds this arcane entry: Note: 720p signals will be converted to 1080i format and output to the display. (sic)
The same reference on page 15 of the PD25U manual reads: Note: 1080i signals will be re-formatted to view on your plasma display.
Not that this necessarily means anything, it could even be a misprint or something lost in translation, but...