Translations:Adventist Youth Honors Answer Book/Health and Science/Optics/57/en
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To take full advantage of the partially mirrored surface, the target side should be brightly lit, to obscure any hint of light coming through the glass from the viewer's side. The darkened room is only completely obscured when it is in complete darkness. Sometimes a darkened curtain or a double door type vestibule is used to keep the viewers side darkened.
