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To the Editor:
—The first quotation known to me concerning the observation of the sun or its eclipse in a darkened room comes from Alhazen (Ibn Al-Haitham, AD 965-1038). A translation of this passage (one of the first known references to the camera obscura) is given by E. Wiedemann in Eder's Jahrbuch für Photographie, Halle, 1910, page 12:"If the image of the sun at the time of an eclipse—provided it is not a total one—passes through a small round hole on to a plane surface opposite, it will be crescent-shaped.... The image of the sun only shows this property when the hole is very small. If the hole is larger the image changes, and the change is more marked with increasing size of the hole. If the hole is very large, the crescent shape of the image disappears altogether, and the light [on the wall] becomes round if the
Linksz A. MORE ABOUT THE ECLIPSEHistorical. Arch Ophthalmol. 1963;70(1):137. doi:10.1001/archopht.1963.00960050139020