Interlacing comes from the output module or the media encoder. That's where your settings are off. It has nothing to do with frame rate or comp settings.
It is easy to check for interlacing. Import your rendered footage, check the file interpolation, set it to separate fields. Now drop it in the new comp that is double the frame rate of the footage and step through the footage one frame at a time. If it is interlaced than your original interlaced material will show two separate slices in time and your original material will show pairs of duplicate frames.
If you did not set the output module or the media encoder two separate fields then it is probably not interlaced.
Well I understand the logic of what you're saying. And yet each time AE outputs a video file showing the upper/odd fieldAll I am exporting it as is ProRes 422. No fields, no interlacing. I put progressive in and it spits interlaced out
I keep thinking it must be something to do with pixel shape and the 1440 x 1080 size .
Personally and professionally I would never work in or render a non-square format. Any NLE, even Movie Maker or iMovie will automatically convert and fit your non square 1440 footage to 1080.
Besides that hat you end up with nearly 30% more data for further processing.
Personally and professionally, Mr Gerard, nor would I. This is a project I have inherited. As mentioned it is a mix of different video formats (HDV, Digi Beta, Betacam SP, 16mm film and HD). I am, or course, going to streamline them to square pixels.
Meanwhile back to the original question.
The problem was a glitch in FCP (not recognizing the clips that had been de-itnerlaced. I have now just reformatted all the video and brought it into Premiere.
Wishing you a cheery day.
Glad you found the bug (or feature) in FCP. I could not and have not seen the Output Module interlace on it's own or add any metadata to ProRez renders.
I know how messy inherited projects can get. I deal with them all the time.