Preserve letterbox when using Ken Burns

Daniel Rutledge wrote: To make your project 1.85:1 you don't need to start over. You should just be able to open the project settings and change the aspect ratio. As far as the color solids go, this is a basic compositing concept. Put the solids as connected clips above the clip you are animating. They should not be inside the compound clip you are animating. To find the correct placement for the bars: put a video clip on the timeline, apply the letterbox effect to it. Place two black color solids above it, then adjust the color solids so they match with the desired letterbox. This all works.

Ahh, I see...

Have been trying to get this to work, but I must me doing something wrong. Can't get it to work.
But I dropped the compound clip and converted the time lapse to video(rendering took some time) to get rid for this problem I can't solve.

But thank you for helping me!

BenB wrote: Use an Adjustment Layer (blank title template) to add the letterbox.

Or, create a generator that has an adjustable letterbox, and place it over the whole Compound Clip.

Perhaps I don't understand what you all are saying and therefore doing it wrong. But for now, I don't have to deal with this. I'm saving the tread for future help.

Thanks again, Ben for you help!