A luminaire with a reflector comprising microstructures

A luminaire comprising:

• a light exit window;
• one or more linear light sources positioned to a side of the light exit window and configured to emit light in directions away from the light exit window, each linear light source extending parallel to a linear axis;
• a reflector positioned opposite the light exit window and configured to receive a majority of the light emitted by the one or more linear light sources, wherein the reflector comprises:
• a diffusive reflective surface configured to perform diffusive reflection on received light;
• and
• a plurality of microstructures positioned between the one or more linear light sources and the diffusive reflective surface, the plurality of microstructures or a lightguide within which the plurality of microstructures are formed, being configured to redirect a first portion of light directly received from the one or more linear light sources such that, for each light ray in the first portion of light, the angle, within a cross-sectional plane perpendicular to the linear axis, between the direction of said light ray before being redirected using the plurality of microstructures and the direction of said light ray after being redirected using the plurality of microstructures is from 140° to 180°,
• wherein the first portion of light comprises no less than 30% of the light directly received from the one or more linear light sources.