Unless I am mis-remembering, all Dish signals from the satellite are 1080i, with the 720P signals down (or up?) converted prior to transmission. For those that have 720P TVs, the signal is then converted in the box (receiver) to the correct format.
A clean OTA signal of 1920x1080i should be better than Dish's 1440x1080i, but as we know many stations like to break up their capacity and piggy-back a weather station and a secondary SD program (such as CW) to their HD signal. When stations do that, they may be broadcasting in something like 1280x1080i (or even 1080x1080i) for their main signal, and their signal quality is noticably less.
I think there are a couple of threads on the forum that discuss this "breakage" issue.
Regards,
Fitzie
No. Dish does not down convert the vertical resolution: if they are sent 1080, they send out (uplink) 1080; if they are sent 720, they send out (uuplink) 720. However the horizontal resolution is down-resed, but it still looks GREAT.
I think you are confusing the fact that the Dish HD boxes do not have Native Resolution output, and that we are required to set our Dish boxes to send out to the HDTV a fixed resolution of either 1080i or 720P for HD output (SD resolutions can also be chosen). This means that if you pick one output resolution the other must be converted to match the output you've set it to just before output of the box to the TV. And, of course, all the SD has to be up-converted to your chosen HD resolution output. All this conversion does degrade the PQ somewhat, although some people would never see the difference, but the PQ is not at optimum, and I'm certain that some TV's do a better job than the Dish box of converting if they are handed native resolution.
That's the problem. Too many broadcasters are cramming in a lot of sub-channels because of real world economic considerations that lead them to sacrifice the main channels HD quality for some sub-channels. and so, the promised and supposed knock your socks off OTA HD is not the reality, today in far too many places. Still impressive, but not the blow you away HD at full bit-rate.
OTA broadcasters can still broadcast in full 1080i resolution, but it is the bit-rate that is decreased to make room for the sub-channels, and that is why the OTA's main HD may not looking as good as it could. But even 12Mbs OTA HD can still look great. Full bandwidth with a great source and an engineer at the station who knows what he is doing, and a lot don't, especially in smaller cities, is STUNNING.
I do have to close by asking those who remember how utterly knock your socks off great Dish's HD feed of the Democratic National Convention was last year. Man, watching that made it clear the sacrifices to the HD PQ Dish was making on all its other HD channels. The DNC HD feed must have been full resolution and full bit-rate. I still have it on my external HDD, and it is still how HD should be done. Overall I am satisfied with Dish HD, but I do wish Dish could uplink full HD resolution at full bit-rate, or equivalent to full bit-rate using their 8PSK and Turbo Coding technology.
