The present invention provides for a device for blocking direct light from a light source, wherein the device comprises two arrays of elongated slats and a means to coordinately move the two arrays relative to each other within a range of configuration, wherein in at least one configuration the two arrays block direct light from a light source to more than one location incident to the light source while not blocking other views through the two arrays from the more than one location.
STATEMENT OF GOVERNMENTAL SUPPORT
 The invention was made with government support under Contract No. DE-AC02-05CH11231 awarded by the U.S. Department of Energy. The government has certain rights in the invention.