I need to downconvert from 720P to SD (for BetaSP), and I need to add text and graphics to the letterbox black stripes. Right now I'm doing it with the FCP sequence presets, but I haven't been able to preview it properly in my monitor. Is there a way that I can edit in 720p in 4:3 without losing quality? What is the best way to downconvert in this situation?
If this is a 59.94 720p project, simply go into the Kona Control Panel, select the analog tab, and downconvert to 525. It's real easy to do this, and has nothing to do with the FCP application. It's all done in the Kona Control Panel.
They have a plug in that will generate title safe areas for you for different aspect ratios (such as a 4:3 center cut like you want to do). That way, enter in the text in the widesafe areas comparable to a 4:3 crop in NTSC, and then do what Bob says.