The opticians at �The Sign of Isaac Newton and Two Pair of Golden Spectacles� sold a range of optical toys and instruments, barometers, thermometers...
Chancellor Gordon Brown is reflected in a convex mirror as he walks into the Treasury on March 21, 2007 in London. This is likely to be Mr Brown's...
Engraving depicting the arrangement of lenses in Johannes Kepler's telescope. This had two double convex lenses and gave a wider field of view....
Concave and convex curvatures of lenses bend, or refract, light in opposite ways, depending on the focal length of the lens and on the distance...
old engraved illustration of line curves in geometry - logarithmic spiral, equiangular spiral, or growth spiral - 凸形 ストックフォトと画像
