I expect this to generate some debate:

We all know the 3 Star Wars prequels were shot (in varying amounts) on modified HDCAM cameras, in 1920x1080p.

My question is: what resolution was the actual D.I. and CGI work done in?

Could it be possible that Lucas was not as self-limiting as many assume, and he actually mastered those films in 4k or higher?
Now I know the "live" footage was only HDCAM/2k, but perhaps that would not be so noticeable after compositing into a 4k+ CGI environment. Since virtually every scene is 90% CGI, would we really notice the actors themselves are only 2k?

Maybe Lucas is saving an ultra-hi-def version for later release?

My money is on a 4k+ CGI environment. I refuse to believe Lucas would limit his future exploitation of the movies by only rendering in 2k/HDCAM resolutions.

Just pondering.....

I think I remember reading somewhere a long time ago the cgi was 4k....

It's all over the internet: the CGI used was 4K. Just Google around...

"The Phantom Menace" was shot in 35mm anamorphic (Hawk lenses, Kodak negative).
"Attack of the Clones" was shot mostly on the Sony F900, mostly recorded to HDCAM.
"Revenge of the Sith" was shot mostly on the Sony F950, mostly recorded to HDCAM-SR.

Generally ILM did their effects work at 2K, not 4K, at least as far as I've heard from ex-ILM people.

If Lucas wanted to future-proof his movies at 4K resolution, he wouldn't have shot the last two prequels with HD cameras. Even "The Phantom Menace" went through a 2K D.I. more or less at ILM.