In the evening of December 22, 2007 Emil Brezina had the opportunity to observe halos on cirrostratus clouds from the top of Lysa hora, the highest peak (1323 m) of the Moravian Beskydy mountains.
Among these halos, there was an expressive sunvex Parry arc, which can compete in brightness with diamont dust halos. The development of the Parry arc and upper tangent arc was photographed between 3:17 and 3:34 pm, and further photos of the display are also available. ( 1 - 2 - 3 )
By chance I (Martin Popek) observed the same sunvex Parry arc about 20 km from Lysa hora but the quality of the photos cannot be compared. ( 1 )