Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 20
Fig. 3.—A method of painting a largebuilding. horizontal appearance where most of thelight is reflected or refracted. Grasspressed fiat naturally reflects light up-wards and that is why tracks show alighter tone. The slightest disturbancein a field originally photographing aneven tone is shown up… … Fig. 4.—Aerial photograph showing various tone values of different growths of vegetation. 16 THE ILLUMINATINC4 ENGINEER (jan. 1920) The study of tracks is all-importantto the intelligence officer. They recordmovement of troops with unerringaccuracy and it was only during the laterphases of the war…
Lighting
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