CIE 184:2009

The CIE recommended daylight illuminants in 1967. These daylight illuminants contained ultraviolet radiation in proportions as found in natural outdoor daylight. Indoors this daylight is filtered by the transmission of the window glass; therefore it became necessary to define spectral power distributions also for the indoor daylight phases. The TC recommends adoption of two indoor daylight illuminants ID50 and ID65, that correspond to the phases of daylight of about 5000 K and 6500 K

The publication is written in English, with a short summary in French and German. It consists of 22 pages with 5 figures and 2 tables. correlated colour temperature. Tables of the spectra are provided at 5 nm intervals from 300 nm to 780 nm, along with the rationale for their development and detailed comparison with existing daylight illuminants.