ZARDOZ (1974), written and directed by John Boorman, cinematography by Geoffrey Unsworth, starring Sean Connery.
I can take movies that are goofy, that are non-sensical, that are just plain weird--and ZARDOZ is all of that--but movies that tell and don't show are not good cinema. And that's the main flaw with ZARDOZ. The director seems so full of his grand ideas that he has the characters standing around explaining what happened and the visuals don't carry the movie--even though there's lots to look at. However, Boorman would have probably needed an even bigger budget to realize all these big ideas properly on screen (the budget was over a million dollars which was considered large at that time).
It seems a pretty daft movie for Boorman who has better movies to his name--but maybe it's one of those things he needed to get out of his system before he could do more coherent work.
Visually, in the comics, Vartox is based on Connery's character named Zed in this movie. The people on Earth in the year 2293 live in their own community bubbles and each is called a Vortex. Their so-called god is Zardoz. So combine Zardoz with Vortex and you get Vartox. Cary Bates must have seen the movie right when it first came out and then rushed home to write the first Vartox story, given that came out only six months after the movie and it took about six months from script to published comic on the spinner racks.
The ruling class in ZARDOZ are the Eternals. Jack Kirby's Eternals debuted in 1976--it seems reasonable to me that the name of them came from this movie.
That's two comic book connections. And the cinematography for both ZARDOZ and SUPERMAN (1978) was by Geoffrey Unsworth.