German photographer Paul Schneggenburger takes pictures of couples sleeping together throughout the night, and the results are both intimate and eery.

"What happens to lovers while they are sleeping?" Schneggenburger wonders in his artist statement. "Is it a sleeping just next to each other, each on his own, or is there a sharing of certain places or emotions? Is it a nocturnal lovers’ dance, maybe a kind of unaware performed tenderness, or does one turn the back on each other?"

Each picture from "The Sleep of the Beloved" series was shot as black and white, long-time exposures taken over the course of six hours. The room with the bed was in the artist's live-in studio — Schneggenburger would turn on the self-constructed "timer" of the camera and leave while the couples slept.

The project began as his thesis work at the University of Applied Arts in Vienna in 2010, but has since become a long-term project that anyone can take part in.

The photos are currently on display at the Anzenberger Gallery in Vienna.