Reflections in Water

Abstract

IN the coloured photographs from Egypt, printed in The Illustrated London News on February 25, one picture has white clouds and blue sky with their reflection in still water. The image has the appearance of being stronger than the original. The fact is that the blue sky has much more polarised light than the clouds: the cross-polarisation by reflection at the water darkens the sky and scarcely alters the clouds. At the various incidences, by which the different points of the sky reach us, the conditions are altered. Thus the reflected scene is one of greater variety and stronger contrasts. The effect is not due to anything in the photographic process; I was surprised to see such a correct presentation of what I have sometimes observed.