Thank you for helping me, Jeff. Maybe I should say more about this project. I shot this film years ago. I think I can safely say that the black bars don’t depend on the playback.
I recall struggling with importing the raw footage. I had to capture it in Final Cut, then bring it into Premiere. I think I had to conform it to square pixels (if i remember correctly). At the present, I have reopened the old project and imported the upscaled version of the finished film for the sole purpose of adding subtitles to the upscaled version. I’m doing this in order to be able to enter festivals and to have a nicer HD version on the web. I can replace the upscaled version with the SD version in the timeline, as you said I should and work with that.
Please note that Ann Bens said that even if I succeed in removing the black bars, YouTube will put them back anyway and the film festival projection will do the same. That would mean I’m wasting my time, but I assume that would only be the case if the finished cropped aspect ratio was not 16/9. Can I really crop it to a perfect 16/9? If Ann is right then I’m wasting my time. Please advise me on that!
BTW I’ve been using the word footage to mean the two versions of the finished film. I don’t have the raw footage with me.