FX for Anamorphic Composite


I’m not sure if this is the right place in the forum for this question but let me give it a shot.

I have done a fair bit of compositing for various projects, like set extensions, adding objects into scenes, tracking and object replacement, etc. I was recently talking to someone about creating FX for compositing into Anamorphic footage and realized I don’t know anything about it.

I was hoping someone could explain how extensions and such for anamorphic footage differs from doing it on typical footage? For instance, in a movie like Star Wars, which I understand was shot in anamorphic, what do the insert graphics need to look like? Is there some way to export anamorphic 4x3 our from 3D apps which accounts for the lens distortion? Is there are reference or resource you could point me to?

Thanks in advance for any insight