Saul Bass - one time director

In 1974, Saul Bass directed one and only full feature, a sci-fi flick called Phase IV
It's not the greatest movie, but it's said to look beautiful. (There is a great series of screenshots to show this.)It starred Nigel Davenport, Michael Murphy, Lynne Frederick and Helen Horton.

The plot:

"A species of superintelligent ants is detected in the Arizona desert, mad-bad scientist Nigel Davenport plus assistants Michael Murphy and Lynne Frederick construct an experimental dome there to study them. The ants have destroyed all their natural enemies, and are now interested in conquering the last: Man. Facing an onslaught, the characters experience the mystical, rather inscrutable dawn of a new evolutionary era." (via)

YouTube has the whole movie in parts. Part 1 is below. Watch the rest:Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8 & Part 9.
(credit: @DesignFacts)