Question

define. a) longitudinal chromatic aberration​

Answer 1

Answer:

Longitudinal chromatic aberration (LCA) occurs when different wavelengths focus at different points along the horizontal optical axis as a result of dispersion properties of the glass.

Answer 2

Explanation:

The longitidinal chromatic aberration leads to colored areas in the images, that arise, because not all three colors can be displayed in focus.Obliquely incident light leads to LATERAL CHROMATIC ABERRATION. In that case all colors are in focus in the same plane, but the foci are not placed along the optical axis.This kind of aberration does not lead to colored areas, but to fringes that occur around objects of high contrast as the magnification is dependent on the wavelength.chromatic aberration is to use different lenses in one optical sytem. Different types of glasses refract light in different intensities, so if you combine differing glaastypes, you can reduce aberrations. An example is an achromat, an optical system that combines a refracting and a dispersing lens.

The convex lens refracts the beams of short wavelenghts (blue) stronger than those of long wavelenghts (red) and the concave lens, that comes afterwards, does the opposit: it spreads the red beams stronger than the blue ones. It comes to a compensation of the focus difference and the different light beams meet in one focus.