Читать книгу Magic Shadows. The Story of the Origin of Motion Pictures онлайн

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Kepler wrote, “This art, according to my knowledge, was first handed down by Giovanni Battista Porta and was one of the chief parts of his Natural Magic.” (But, as the reader recalls, Porta was not the first to know about the camera obscura and was not its inventor but only a popularizer.) “But content with a practical experience,” Kepler continued, “Porta did not add a scientific demonstration. Yet only by the use of this device can astronomers study the image of the solar eclipse.”

Kepler then described the camera obscura or “dark chamber,” adding an interesting observation. He proposed that the spectator should keep out of the daylight for fifteen minutes or a half hour before he planned to use the camera so that he could get his eyes accustomed to the darkness in order to observe the images more clearly. Kepler then instructed that the objects to be represented should be placed in bright light, either of the sun or lamps. He also noted that the objects were reversed, and remarked that the images appeared in the colors of the objects. Kepler also explained that a diaphragm was needed to control the amount of light admitted to the camera, and that best results were obtained when the sun was near the horizon.