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It's more enjoyable to shoot in a studio on a single location with two actors... if they are good.

"Michael Haneke Talks AMOUR, His Inspiration for the Film, His Casting Decisions, Physical and Emotional Demands of the Film and Shooting the Film in French". Interview with Sheila Roberts, collider.com. December 14, 2012.
It's more enjoyable to shoot in a studio on a single location with two actors... if they are good.