Question

List the various types of aberrations. What causes them and how can each be reduced?

Short answer

The different types of aberrations are Chromatic, coma, and spherical.

Step-by-step solution

Definition of aberrations.

Aberration is a distortion in an image.

Types of aberrations.

Some types of aberrations:

Chromatic: Since the index of refraction of lenses depends on color or wavelength, images are produced at different places and with different magnifications for different colors. using mirrors can remove this problem, but diverging lenses can only alleviate it.

Coma: Quite often in an imaging system the object is off-center. Consequently, different parts of a lens or mirror do not refract or reflect the image to the same point

Spherical rays converging from the outer edges of a lens converge to a focus closer to the lens and rays closer to the axis focus further.