Aspherical lens
A component of a lens that has a surface that is not precisely spherical in shape. Every lens used in a camera is actually composed of a number of smaller lenses known as elements. Many of these components have a spherical shape, giving the impression that they were extracted from a sphere. Aspherical elements are less rounded than spherical elements, and they are employed in wide-angle and wide-aperture lenses to help deliver images that are free of distortion.
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