Haven’t used Final Cut in a while. I’ve never used final cut with an anamorphic lens or a Helios fake anamorphic lens. I took some at 3.5 K footage and every time I Exported the video it always came out in a box. Are used letterbox in final cut pro and change the aspect ratio but it still comes out in a box. The test footage is below. https://youtu.be/GkdRJ2TaB0E

Hi - AFAICT it doesn't seem to be a problem with aspect ratio, just size, so maybe check the Clip dimensions vs the Project dimensions to see if there's a mismatch (with the Clip dimensions being smaller), and if there is , adjust accordingly..? I'm an audio guy myself and not a regular FCP user, so I can't offer more specific advice, but I've attached a FCP course to this thread -- maybe there'll be something helpful in there, or perhaps a regular FCP user/guru will respond with advice. I also found these documents, FWIW.. https://macprovideo.com/article/apple/understanding-project-properties-in-final-cut-pro-x https://support.apple.com/guide/final-cut-pro/modify-a-projects-settings-ver4353c0d3/mac https://support.apple.com/guide/final-cut-pro/conform-frame-sizes-and-rates-ver3363b44e/mac

Thanks joe I’ll take a look

You’ll want to use a Custom project size if you want to avoid black bars of any kind, but you can choose any size you wish. To correct the anamorphic clips to match, you can adjust Scale X or Scale Y, depending on the size you want to work in. Spatial Conform can also make a difference.

that might be the problem. I have it set to none. Should I have it to fit?

By all means try the other settings, but you probably don’t need the letterbox effect either. If you use a custom project size then you don’t need to add black bars.