The Silver Sunbeam: A Practical and Theoretical Text-Book on Sun Drawing and Photographic Printing; Comprehending All the Wet and Dry Processes at ... Wax, Resin and Silver (Classic Reprint) - Couverture rigide

John Towler

Couverture rigide

ISBN 10 : 0266534503 ISBN 13 : 9780266534501

Editeur : Forgotten Books, 2018

Synopsis

Excerpt from The Silver Sunbeam: A Practical and Theoretical Text-Book on Sun Drawing and Photographic Printing; Comprehending All the Wet and Dry Processes at Present Known, With Collodion, Albumen, Gelatin, Wax, Resin and Silver

Sun-drawing, Heliography, and Photography are synony mous expressions for the same phenomenon, although ety mologically the two latter are somewhat different - helio graphy signifying sun-writing, whilst the word photography signifies light-writing. Not one of these expressions is strictly correct, because actinic impressions can be obtained from rays emanating from the moon, from artificial light, or the electric spark. Actinic drawing would probably be the best name, although as regards the representation of facts by words, it is immaterial for the masses of mankind whether these words have an intrinsic or root-meaning or not. The phenomena comprehended under any one Of the above syn onymous expressions, depend immediately upon what is termed light as the force or cause, and upon the property, which only certain substances apparently possess, of being affected according to the intensity of the light employed. The principal of these substances are the salts of silver, the salts of iron, bielzromate of potassa, and certain resins, as the oil of lavender and asphaltum. That light acts upon or ganized substances is a phenomenon which must have been Observed by the first occupants Of earth; they could not fail to remark the brilliant hues on the side of an apple that received the direct rays Of the sun, and to contrast these resplendent mixtures Of red, crimson, green, purple, yellow, orange, and other colors, on the one side, with the white, or greenish White, on the side exposed simply to the diffused light of day. The variegated foliage of a tropical clime, as contrasted with the continual merging into green, according to the increase in latitude, gives evidence of the in?uence of actinic action; and this change of green into white

Détails de l'édition

• Éditeur: Forgotten Books
• Date d'édition: 2018
• Langue: anglais
• ISBN 10: 0266534503
• ISBN 13: 9780266534501
• Reliure: Relié
• Nombre de pages: 398
• Coordonnées du fabricant: Copytech (UK) Ltd, Trading as Printondemand-worldwide.com; gpsr@podww.com; ; 9 Culley Court; Orton Southgate; Peterborough; Cambridgeshire; PE2 6WA; Royaume-Uni
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