A luminaire comprising a housing having thermally separate compartments for an electronics portion and a lighting portion. These thermally separate compartments can provide thermal isolation between the electronics portion and the lighting portion. The lighting portion comprises a plurality of light-emitting elements and further includes an optical device comprising two linear diffuser elements and can be used to further improve the light emission characteristics of the light-emitting elements thereby providing a directly viewable luminaire wherein the illumination produced by point light sources appears uniform along the length of the luminaire. A power supply for supply of energy to the light-emitting elements and a controller for controlling application of energy from a power source to the light-emitting elements is provided in the electronics portion and can be thermally separated within the electronics portion.