Achromatic lensesIn 1758, optician John Dolland, having created achromatic lenses, reported this to the Royal Society. Isaac Newton had described the blurring effect due to chromatic abberation, but could not solve the problem in simple lenses, which was important in the preparation of lenses for telescopes and microscopes. A concave face of a lens of flint glass (which has a greater color dispersion than crown glass) is cemented to a convex face of a crown glass lens. Thus the dispersion properties causing chromatic aberration are removed from both lenses simultaneously. Although Dollond patented the discovery of the achromatic lens in the mid-18th century, it is widely believed that he was not its inventor, but learned about it from lens maker George Bass. |
