Characteristics of Aspheric Lens
Spherical Aberration Correction
One of the most important features of aspheric lenses is their ability to correct for spherical aberration. Spherical aberration is found in all spherical lenses, such as plano-convex or double-convex lens shapes. However, aspheric lenses excel in focusing light to a precise point, resulting in minimal blur and enhanced image quality. Spherical Aberration is the consequence of the uniform curvature of the lens surface and not the result of a manufacturing error. The outer rays converge at a different focal point than the inner rays resulting in blurred or distorted images.
A spherical lens with a significant amount of aberration and an aspherical lens with almost no aberration can be seen(Figure 1). Aspherical Lenses address the issue by deviating from a perfectly spherical shape. An aspheric lens can be designed by modifying the curvature length and adjusting the conic constant and aspheric coefficients of the curved surface of the lens. By carefully shaping the lens, aspheric lenses ensure that all incoming light rays converge to a single focal point. minimizing spherical aberration and improving image quality.