Extra haze sometimes fills the deepest valleys, enhancing the aerial-perspective effect. Berann used greater amounts of mist and haze in middleground areas on his panoramas of the Alps, a humid environment, compared to his NPS pieces of the drier western United States. Moreover, the fluffy cumulus clouds so typical of summer skies are conspicuously absent from Berann's panoramas, perhaps because their languid appearance would contribute minimal dynamic energy to a scene. Berann's most memorable panoramic sky was painted for the Valais Water Authority, a region in Switzerland including the Matterhorn. On this project Berann was free for once from the dictates of the tourist industry, which invariably insisted on showing sunny skies to attract visitors.
Clouds are absent or rare on snow-covered winter panoramas to minimize the dominance of white.
The Denali panorama shows this preference, although a careful inspection will reveal a few wispy clouds emerging from behind the flanks of Mt. McKinley. On most panoramas, clouds are placed at varying altitudes, ranging from fogs, mists, and storm clouds that brush the Earth's surface to streaks of cirrus high overhead. With theatrical drama, Berann typically placed roiling storm clouds along the margins, where they appear to be moving away from the center of the panorama. The effect is to reveal a landscape to the audience the way opening curtains reveal a stage.