A camera obscura is a box or darkened room with a lens or hole, through which the image of an external object is projected onto the opposite internal wall. Camera obscuras were known to the ancient Greeks and Chinese, and were used by Arab astronomers in the 10th century to observe the Sun. During the Renaisance period, artists used camera obscuras to help them to draw more accurately. In 1778 William Storer designed a camera obscura of such technical superiority that it did not require strong sunlight to produce a distinct image, and could just as easily be used by candlelight. It was granted a Royal patent and named the 'Royal Delineator'.
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