Why is it so dark in here? Perception of Brightness at Low Light Levels in Museum Environments.

Many museum and gallery exhibits are fragile objects that would not survive repeated handling. Even where this is not the case, it is generally frowned upon for visitors to touch exhibits. As a result, vision is by far the most important sense for museum visitors. The author’s 18 years of experience of conservation lighting led to the recognition that, at low light levels, there is a strong correlation between colour temperature and perceived brightness. This is evidenced when curators dim down lighting schemes measured at below 50lux because they claim "it looked too bright to be 50lux", believing that a dim orange light signifies conservation levels.