Brightness, lightness, and providing ‘a preconceived appearance to the interior’:

,!Waldram’s concept of designing a distribution of lighting to provide ‘a preconceived appearance to the interior’ is examined, with particular regard to application of the ‘apparent brightness’ concept. Some recent research into luminance/brightness relationships is reviewed, and it is concluded that brightness, as it is generally understood, does not provide a valid basis for designing interior lighting. The role of ‘visual constancy’ is discussed, and also the ‘modes of appearance’ concept. The latter is proposed as a useful descriptive framework for ordering readily-observed visual phenomena that influence the appearance elements in an illuminated interior. This approach leads to an understanding that brightness and lightness relate to distinctly different aspects of appearance, and this leads to the reappraisal of the role of brightness in influencing the appearance of an illuminated space. These concepts are set into the context of the holistic approach to lighting design that Waldram proposed in hi...