The Black-Drop Effect during the Transit of Venus on June 8, 2004

The black-drop effect during the 2004 transit of Venus against the Sun has been observed and photographed by amateur astronomers in Montreal, Canada. It is shown in this report that the black drop can be explained by the contact then the disappearance of the halos surrounding Venus and the Sun at contact point. The black drop thus appears to be a real part of the disk of Venus and not an illusion of optical perception.