A method and apparatus involve collection of radiation with a radiation collector that allows entry of external radiation. The exterior of the collector has mutually exclusive first, second, third and fourth surface portions oriented so that they each effect total reflection of the majority of radiation within a waveband that impinges thereon while propagating within the collector. The first and second surface portions are spaced and approximately parallel. The third and fourth surface portions extend at a first angle with respect to each other, and respectively extend at second and third angles with respect to end portions of the first and second surface portions.