blu-ray

I have a 50 inch samsung dlp hdtv that is 720p. I bought my first blu-ray movie, which was 300 and an hdmi cable. When i played the movie, it said that it was playing the movie at 1080p. It looks like crap, it looks grainy. I was very disappointed. Will every blu-ray look like this and why does it look this way. When i play my ps3 games they look amazing. I googled this problem and didn't find a good explanation. A good explanation would be appreciated.

Sorry, i realized i posted this in the wrong place.


Thanks,
Pizzle

wrong place, this is the psp bit

on the blu-ray player try changing your settings so that it plays at 720p not 1080p