I know there are several posts on this issue, and I have read them all and tried everything as far as I can tell. Thanks to the Creative Cow research I've already done, I am close to the final answer but not there yet.
So here it is: I shot a movie on Super 16mm film (yes it was a few years ago) and I had the film transferred onto Mini DV to import into FCP. So basically the imported footage that I edited is NTSC 3:2. That is the aspect ratio that was set automatically for the footage upon import and it looks perfect.
Within this 3:2 FCP frame the 1.66 Super 16mm ratio is of course letterboxed. I can live with that. So I finished the cut of the movie and whenever I exported it as a Quicktime mov. it was stretched horizontally. From Creative Cow research I know the export issue is related to pixel shape - square vs. rectangular. On these forums I found two solutions which made my images look good on export to Quicktime. One option was to change the frame size sequence settings to "CCIR 601 NTSC Sq 4:3." The other option was to simply drag my edit into a 16x9 timeline and export from that.
Like I said, both these options keep my images looking fine after export, EXCEPT the movie incorporates title cards throughout, and of course opening and end credits. And both of these methods distort the text in ways I can't figure out how to control. Pulling my edit into a 16x9 timeline distorts the text immediately, and trying to fix the distortion in the Text Motion tab doesn't work because that distorts the actual characters which seem to look fine.
The issue seems to be that when I pull my NTSC 3:2 footage into a 16x9 timeline, the imported visual footage maintains its aspect ratio (with appropriate pillarboxing on both sides) but the FCP generated text fills the 16x9 frame fully, distorting itself and overhanging the aspect ratio of the footage.
Does anyone know how I can maintain the aspect ratio of my text in this situation?? This is really driving me crazy. I was hesitating to even post because I didn't even know if I could explain the problem.
What you shot on is now completely irrelevant. You are editing miniDV 4:3 SD footage. Which is, 720x480. If you do the math, you'll find 720x480 isn't 4:3. But it is, because the pixels aren't square.
That said, if your edit is destined for computer screens, then you need to make sure you're using square pixels on export. Because TVs support non-square pixels in SD, and square pixels in HD. Computers are square across the board. So, STILL edit in native miniDV, 720x480, etc. But when you export a quicktime for YouTube or whatnot, make sure you're exporting to 640x480 in the end.