"false" . "SDN:L22::TOOL1478" . "An optical device that renders distant objects more distinct by enlarging their images on both retinas of the observer. They are used for observation of distant objects on the Earth's surface. Unlike telescopes, binoculars present two images from slightly different viewpoints, producing a merged view with an impression of depth for the observer. Reflected visible light is converged via two objective lenses to magnify the view, which is initially inverted. An erect (non-inverted) image is achieved either by an erecting lens or a prism. Porro prism binoculars use a pair of porro prisms in a Z configuration to erect the image, offering a bright image and good depth sensation. Roof prism binoculars are more compact as the objectives lenses are in line with the eyepieces, but produce images with reduced brightness. Very small instruments may be of the Galilean type, which yields an erect image using a positive objective lens and a negative eyepiece lens. Hand-held binoculars typically use objective lenses 25 to 50 mm in diameter with 7x to 10x eyepiece magnification, but this can vary."@en . "1" . "2020-06-04 16:56:25.0" . . "2020-06-04 16:56:25.0" . "1" . . . . . . "Unspecified binoculars" . . "Unspecified binoculars"@en . "SDN:L22::TOOL1478" . "accepted"@en . . "Unspecified binoculars"@en . "SDN:L22::TOOL1478" .