An edge-lit backlight comprises a front and back reflector forming a hollow light recycling cavity having a cavity depth H and an output region of area Aout, and one or more light sources disposed proximate a periphery of the backlight to emit light into the light recycling cavity. The light sources have an average plan view source separation of SEP collectively having an active emitting area Aemit, wherein a first parameter equals Aemit/Aout and a second parameter equals SEP/H. The first parameter is in a range from 0.0001 to 0.1, and by the second parameter is in a range from 3 to 10. The front reflector has a hemispherical reflectivity for unpolarized visible light of Rfhemi, and the back reflector has a hemispherical reflectivity for unpolarized visible light of Rbhemi, and Rfhemi*Rbhemi is at least 0.70.