Both movies, made ten years apart, take on subjects that are blurry, unreliable, and indistinct. F for Fake focuses on art fraud and the implications of the art of fakery, while Sans soleil focuses on time and memory.
Sans soleil is a travelogue of thoughts, narrated with letters from a fictional female traveler. While commenting on what she observes on her travels - through Okinawa and Tokyo, to Guinea-Bissau, to Cape Verde, to Iceland, to San Francisco - sounds and images cross and contrast. Memories blend and escape and become clarified.
F for Fake is a whirlwind in pace and personality from director/writer/narrator Orson Welles. The film seems to center around Elmyr, a legendary art forger who reproduce pretty much any work of art one can name. Yet there are multiple layers leading to and away from this center, searching to find if there are really any differences between art and forgery.
The narrators determine the tone in both features. Orson Welles is more of an overtly assertive force in his film than Chris Marker's female narrator in Sans soleil. Marker's narrator, though, is the only anchor in the cross-contintental flurry of associations; a quiet but vital guide whose opinion may be subtle but no less dominant than Welles' in the world of each film.
Both Sans soleil and F for Fake are held together by crisp editing and imagery. Sans soleil's pallette is slightly more washed out, leaning towards whites and grays and blues and browns to complement its more meditative feel. F is for fake has a wide array of colors, featuring bright sunlight and yellows and reds and vibrant shades of other colors until the more thoughtful or important sequences settle into a bluer mood.
I'd place F for Fake first in the double feature, for its surprises and more outgoing personality will have greater impact when viewed first. Sans soleil can function as an extension, a tangent of the experiences felt while watching F for Fake, and is long and varied enough to emerge on its own in the mind. What both films offer is a way to break down, but not destroy, information we process through our senses; to not so much reevaluate as better appreciate everything we hear and see.