Admittedly it's just a cheap Visio 32" that we have out on our deck. I know that part of the lighting issue is from the bright background when watching when it's daylight out. But as I said, with the older movies I don't have the issue with either lighting or sound.What resolution is your TV? Also there could be settings related to movies vs standard TV show, and then there is the resolution at which the source material is being streamed, along with compression of the signal.
Basically, it could be your TV and it's settings as well as potentially the resolution at which the movie is being streamed, etc.