Originally Posted by milacqua
If I hook up the Dishtv receiver, which is set on 1080i to the OPPO via HDMI, and let it upconvert it to 1080p, ...
Does the DishTV STB only have a FIXED setting, so that everything it puts out is 1080i including 720p source programs? In other words, will 720p programs be upconverted by the Dish STB to faux-1080i for output because of this FIXED setting? Or is there a "native" setting on the Dish STB to feed 720p source as untouched 720p output to the 103, and 1080i source as untouched 1080i output to the 103? Ideally, this "native" setting is what you want to use... for best final resulting image quality on your display, and done automatically by the STB and with zero involvement by you in making that happen.
When feeding the external HDMI inputs of the 103 the best image quality results on your HDTV will come from feeding "native" from the source device (i.e. the Dish STB) to the 103, letting the 103 do all the cleanup and upconversion to 1080p from whatever "native" source (720p or 1080i) you feed it. You don't want to have the Dish STB doing its own upconversion first as well (e.g. for 720p to faux-1080i), and then also have the 103 upconvert from faux-1080i to 1080p for delivery to the display.
Yes, there are some consequences to using "native" resolutions out of the Dish STB, such as possible delays or brief black screens (due to HDMI handshakes when changing resolutions). And if no "native" is available, then you would need to manually change output resolution on the STB yourself. Sure, these are nuisances. But if best possible image quality on the display is your goal, your best setup is to feed 720p or 1080i to the 103 exactly as they are, untouched by the STB... accomplished either automatically if "native" is available, or manually if there is no "native" possible. Note that there will likely be none of these artifacts if you simply go to another channel or recorded program with the same resolution as whatever it is that you're currently watching. They only occur when changing resolutions.
It's up to you and your tastes and criteria to decide if you can see the output difference on your display when feeding true 720p source from the STB or when feeding STB-upconverted 720p->faux-1080i fed to the 103. You'll notice this difference most easily on ESPN and FOX sports high-speed events, so try it for yourself to see if it matters and if you can notice it. Then you can decide if the "inconvenience and nuisance" of "native source fed to the 103" (either automatically via "native" setting if available, or manually otherwise) is justified. Best results come from feeding 720p as 720p to the 103, and letting the 103 upconvert from 720p to 1080p.