I've got a simple Premiere project containing a mix of different "vertical videos" (aka videos shot upright with an iPhone). When I'm editing it, it looks fine, but when I go to Export Media, the only option I'm given is 720x480, which ends up adding black bars to the video. I just want to export the video in the original size without the black bars. How can I do this?
In Premiere Pro, if you change your sequence size to match your source, you can export the vertical video that way. In the project panel, right click your sequence and change the frame size to the frame size of your video.
You can then export with the preset of
Match Source (the bitrate depends on your project needs).
Additionally, you can also export the video with the preset of your choosing. Uncheck the "Width and Height" and type in the appropriate resolution (example is below).
I don't know all the bits that go into how Export Media chooses the default exporting format (i.e., whether based on timeline, some other deeply hidden preferences, etc), but I do know how to change it. From the dialog box that opens up, click on the video tab and choose the custom video format you want.
For more information, here's the Adobe manual page for exporting workflows.