The standards conversion is no longer and issue and hasn't been for many years now as this has been handled digitally for many years now and is very affordable. It's not the 1970's anymore and hasn't been for nearly 4 decades. The conversion to NTSC will look as good as the original format, provided the original was a good source to begin with.
Some internationals take advantage of the fiber optics to get some services or programming here, and it can look good.
To really answer your question, however, is that Dish is not providing these internationals as good as they can appear because Dish is cramming them all on the 118 FSS Ku satellite along with some LIL. The PQ at 118 is blurry, while the same channels looked very good at the wings of 148 and 61.5. The irony is Dish (or Echostar) is the entity that does provide the services to bring in a number of these international channels using fiber optics and high quality standards. Then Dish blurrs them so bad to fit them onto the 118. The internationals that have high broadcast standards such as NHK, TV5, all look pretty bad on Dish because they look so blurry.
When it is the channel's fault for poor PQ, the biggest factor to international PQ quality is the lack of high standards for what they air. In other words, the channel itself will be in good quality all the way through to Dish and somewhat blurry after Dish compresses it, but the channel will air some of the worst prints of movies poorly tele-cined with horrible color and lots of damage apparent or they will are video that, again, was very poorly produced with lots of noise and impairments. The PQ is only going to be as good as the channel's technical standards for "air" or "broadcast" quality content that it airs.
Think of the smallest local channels in your city or the smallest PBS station in your city compared to the biggest. They had a pretty good signal and could produce very good quality PQ in that there was nothing wrong with what the FCC allocated to them to broadcast on. The problem was that those little channels aired content that was in crap condition and produced shows in video with inferior equipment that caused noise and the video tape used for production was damaged, too, often because of no money or the lack of will to spend it. That's the international PQ situation.
