File:EB1911 Vision - Experiment of Scheiner.jpg
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Summary
| Description |
English: Diagram of experiment of Scheiner: Let C be a lens, and DEF be screens placed behind it. Hold in front of the lens a card perforated by two holes A and B, and allow rays from a luminous point a to pass through these holes. The point o on the screen E will be the focus of the rays emanating from a; if a were removed farther from the lens, the focus would be on F, and if it were brought near to C, the focus would then be on D. The screens F and D show two images on the point a. If, then, we close the upper opening in AB, the upper image m on F and the lower image n on D disappear. Suppose now that the retina be substituted for the screens D and F, the contrary will take place, in consequence of the reversal of the retinal image. If the eye be placed at o, only one image will be seen; but if it be placed either in the plane of F or D, then two images will be seen, as at mm, or nn; consequently, in either of these planes there will be circles of diffusion and indistinctness, and only in the plane E will there be sharp definition of the image. |
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| Date | published 1911 | |||
| Source | “Vision,” Encyclopædia Britannica (11th ed.), v. 28, 1911, p. 132, fig. 5. | |||
| Author | Unknown artist | |||
| Permission (Reusing this file) |
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 23:03, 28 August 2021 | | 879 × 274 (56 KB) | Bob Burkhardt | {{Information |description = {{en|1=Diagram of experiment of Scheiner: Let C be a lens, and DEF be screens placed behind it. Hold in front of the lens a card perforated by two holes A and B, and allow rays from a luminous point ''a'' to pass through these holes. The point ''o'' on the screen E will be the focus of the rays emanating from ''a''; if ''a'' were removed farther from the lens, the focus would be on F, and if it were brought near to C, the focus would then be on D. The screens F a... |
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