Many THX certified discs feature a handy calibration tool called the THX Optimizer. How well does this tool work? It says that the changes should only apply to the specific film you are watching; is it best to restore the previous settings when watching other films?

Are you sure about that? All THX certified movies should be "mastered" to the same pallete of sorts, shouldn't it?

Besides, the only thing that those THX test patterns do is to give you a black level and color saturation and tint setting to set your TV at. Should be the same for all movies.

In general, this is a tool to use basically if you don't have anything else available. Making some color/tint/brightness/contrast adjustments with these standard patterns is better than nothing... especially if your TV is still using the factory settings.

However, if you are really interested in properly calibrating your device -- and anyone who spends and large amount of time watching DVDs should -- you should look into getting a more comprehensive disc, such as Digital Video Essentials.

What he said.

Yup. Or Avia

Digital Video Essentials and the Sound & Vision Home Theater Tune-Up are both excellent calibration discs that cost around $18. There is no excuse for not owning one.

THX Optimizer is inherently flawed in design. You shouldn't rely on it.