I tried changing the format to HD and doing a mixdown and I got a zoomed in and cropped image.

How do you preserve the Frame Size and Aspect Ratio when changing formats from some 4k flavor to

1080 HD?

Im Not in front of my AVID but as I recall you have to deselect the auto size feature

I searced Auto Size in  help and it returned information on exporting files.

I would like to keep it in the Avid Editing domain.  I wonder if this means changing from the DNxHR codec to DNxHD?

Does anyone at Avid know how to convert a 4k edit to an HD project and preserve the Screen size and aspect ratio?

If the sequence is is from 4K UHD format you switch the project to HD, Avid will reformat your clip. Each clip will contain a FX called FrameFlex.

Right click the clip in the source and select Source Settings. From there you can change the FrameFlex parameters.

Thank you for that.

I have been going through an edit and using the effect editor to stretch it out.

It fixed my problem, but, I tried the size sliders ( to get different compositions)  and they don't seem to resize the video.

I rendered it and it left a frame over the video in the right edit window but did not resize or recompose the shot.

Good thing I saw this thread. I need to downcovert a 4k video for my new project.