NEW PHOTOGRAPHY

Dominion, Volume 26, Issue 32, 1 November 1932, Page 9

NEW PHOTOGRAPHY

Infra-red Plates Pierce Haze and Fog MANY POSSIBILITIES By Telegraph—Press Assn. —Copyright. London, October 30. The War Office and the Admiralty are interested in Infra-red ray photography, in consequence of which special experiments have been Initiated at the physical laboratory at Teddington. The new photographic plates overcome haze and fog and give definition as sharp at 20 miles as at 100 yards. If the process is applied to warfare, it is suggested that a smoke screen for a battle fleet will be rendered useless and aircraft will be able to photograph a battlefield or fortifications while hidden in the clouds. Liners will be able to speed through fog because they would know the position of ships ahead.

Scientists could search the vaster area of the universe, and it is thought that the discovery may ultimately be the means of deciding the existence of life on the planets.

It is now no longer necessary for a photographer to wait upon the weather when he wishes to photograph distant objects or scenery which the thickness of the atmosphere prevents him from seeing, stated ‘The Times” (London), recently. His camera has acquired the power of penetrating mist and haze, or rather disregarding them as though they were not, and of recording objects within its range as clearly as though the image were presented through the most translucent atmosphere.

The secret of this new photography can be succinctly explained. One of the reasons why it is impossible to see far in misty or hazy weather is because the moisture in the air scatters the light; but the light is scattered also on a fine day, though less when the light is yellowish or reddish, as toward sunrise or sunset. Red light indeed is scattered less than blue. The problem therefore has been how to use the infra-red light in the atmosphere, and to exclude all the light in the atmosphere which is not infra-red. This is achieved by a so-called filter, a suitably dyed piece of gelatine, placed in front of the lens. It allows infra-red rays alone to penetrate, and to. carry the image; and though infra-red light is invisible to the eye, the sensitive material carried in the camera is responsive to it. Thus by an infra-red sensitive plate, photographs can be taken at a distance not possible in the ordinary way with a telephoto camera, and objects revealed which the eye cannot see. The effect, it is true, is that the appearance of a landscape is altered to the eye; but outlines are true, and are of a distinctness not obtainable before.

A remarkable panoramic photograph of a stretch of the French coast, taken from behind the town of Dover, was reproduced in “The Times” on May 9. The photograph was taken by the new process at a time when the French coast was barely visible to the eye. The outlines of bills and fields behind the coastline can be distinguished in the picture.