English: Black Drop Effect: Individual images extracted from a video sequence of the transit of Venus on June 8, 2004. The individual snapshots were obtained at nearly the same moment, and images with "bad" (left) and "good" (right) image sharpness (due to turbulences in the Earth's atmosphere) are compared. It is clear that the "black drop" phenomenon is more pronounced in the "bad" images. All images were taken within half a minute near the egress of Venus from the solar disc, and the "good" and "bad" images in each row were taken within a fraction of a second. (Note the timestamps in the image.)