[Jeffhs]

There isn't much or anything you can do about Macrovision, as it is a copy-protection scheme to prevent illegal copying of DVDs. If there is any kind of system capable of filtering out Macrovision, I am not aware of it; I doubt if such a filter is available, as it would be itself illegal. Hollywood and the TV production companies have been awake nights trying to foil these systems, as (of course) they do not want their programming being stolen. However, if the brightness of your TV picture varies on standard TV programming as well as with DVDs, the problem is almost certainly in the set itself, probably a CRT bias problem.