Dark Side | Recessed Wall Light by Igor Lobanov from russia
designer's own words:
Dark Side is a range of wall seamless recessed luminaires made of gypsum and concrete.
Seamless recessed wall lights are made of concrete and gypsum.
Turning on the light gives a feeling of spherical volume for central part of the luminaire highlighting its relief and surface bump. 
Principal scheme in cross section
Using different color and color temperature of LEDs coupled with different concretes gives an assortment of luminaires.
shortlisted entries (100)