What would cause the picture on a dvd to get darker and lighter?

I rented three dvds from a store and all of them had this prroblem. The picture would gradually get darker then lighter. It was difficult to see sometimes. I tried other dvds in the same player and didin't have that problem. They didn't have any smudges.

sounds like macrovision copy protection

is the dvd player plugged into a vcr?

if so then try it directly into the TV Usually that sound like a copy protection engagement if going through a VCR or a TV/VCR combo. Is it? If not then check that you have the best connection available on the TV. Meaning that if the TV has s-video connections but you are only using RCAs then upgrade, component video better yet. It might have been coincidence and the problem may be elsewhere. To check this play the DVD again and look at the same scene twice. If the pattern of light and dark are the same both times then the DVD player might have an incompatibility issue with those DVDs. Hope this helps. Mine used to do that, not all the time but when it did it was annoying as hell. Im not sure what DVD player you have but mine was a cheapo which I later threw away after buying a decent one. the smudges was probablt the problem. also if it is hooked up to a dvd recorder it might do that to prevent dvd duplicating

The answers post by the user, for information only, CeQnA.com does not guarantee the right.