Yes, the source signal has to be at least 720p to be considered true HD. Your TV doesn't automatically just make anything input into it true HD. Wow, if only something like that existed! Now these days you have DVD players that will upconvert regular DVD's to 720p and 1080i. These are half step technologies because the source signal is still the 480i or pthat all DVD's are. You just have a really nice pro scan DVD picture. It's not HD at all. You're looking at a nice 480p picture on a nice TV that's handling it well. Switch on Discovery HD and compare that picture. THAT'S true HD.