FILM VIEWING CONDITIONS IN MAMMOGRAPHY

A requirement for a minimum viewing box brightness of 3000 cd m(-2) fo r reading mammograms has been widely advocated. Some recent work has c hallenged that opinion by reporting no significant variation in visibi lity of low contrast and fine detail objects over a wide range of brig htness levels. This paper provides further experimental evidence to su pport the latter conclusion, at least over the range 1340-4190 cd m(-2 ), and suggests that the currently recommended minimum viewing box bri ghtness levels need to be revised. The importance of reducing room lig hting levels is fully confirmed.