An exemplary general lighting fixture includes an assembly forming an optical integrating volume for receiving and optically integrating light from one or more solid state light emitters and for emitting integrated light. The assembly includes a reflector having a diffusely reflective interior surface defining a substantial portion of a perimeter of the integrating volume. A light transmissive solid fills at least a substantial portion of the optical integrating volume. A light emitter interface region of the solid, for each solid state light emitter, closely conforms to the light emitting region of the respective emitter. A surface of the transmissive solid conforms closely to and is in proximity with the interior surface of the reflector. The transmissive solid also provides a light emission surface, at least a portion of which forms a transmissive optical passage for emission of integrated light, from the volume, in a direction facilitating a general lighting application.