OCR
76 LIGHT AND WATER reflecting as it does at this abrupt angle so much less light from the sky, is considerably below the value of that part of the sky which it reflects. One hears it said that water should be painted "a tone lower” than the sky. As a matter of fact, they are in the distance almost equal in value; whilst, on looking down perpendicularly at the water, the difference in value between them is enormous, the blue sky appearing almost black by reflexion. Thus there is a marked gradation in (diminishing) value from the far distance to the foreground, increased by the fact that the upper parts of the sky are darker than those near the horizon. This gradation may be clearly seen in any photograph which includes a water foreground, as, for instance, in the frontispiece to this volume.’ So much for the angle of vision; but the degree of illumination is also an important condition. It has been already noted (page 68) how the colour of water is brought out by direct sunlight, and the difference in the appearance of our duck-pond in sunshine and in shade is very considerable. On adull day, the colour of the water may perhaps be scarcely perceptible a yard or two from the point at which the observer is standing, and looking more obliquely on to the water, it disappears altogether, so that at the further side of the pond the sky seems to be mirrored in all its purity ' Owing to the limited range of luminosity in a photograph, the brightest part of the sky in this view appears no brighter than its reflexion, though the actual difference in tone must have been as great there as in the darker parts of the sky on either side of it. A more natural effect might possibly have been obtained by cutting . away the mesh in this block in the brightest part of the sky.