Radiometry & Photometry Library 

Did You Know?

A recent article in Lighting magazine caught our eye. It refers to the lather that the Daily Mail got itself worked up into at the alleged lack of patriotism of the Selfridges store in Birmingham (pictured above).

The Selfridges building is a standout landmark in the regenerated Birmingham. At night, it is normally illuminated in blue. On other occasions, the building has been illuminated in various other hues (pink, gold and green) to mark special occasions such as Gay Pride and St Patrick’s Day. The Daily Mail argued that the building should be illuminated in red to mark St George’s Day.

Unfortunately for the Mail journalists, the laws of physics prevent Selfridges from honouring the English patron saint. The building is indeed illuminated with red lamps, but the spectral reflectance of the tiles on the building preferentially reflect blue wavelengths. Hence the building appears pink.

This is a perfect illustration of the problems lighting designers have in achieving their desired colour rendering. Colour rendering is one of the topics we cover in our Practical Light and Colour Measurement Course, delivered in association with Birmingham-based Photonics Cluster. To learn more about the course, click here.