What is lens dispersion?

Lens dispersion phenomenon: dispersion will affect the color purity and indirect sharpness of imaging, that is to say, the photos taken by the dog-head lens with large dispersion are not correct and rich in color, and the clarity is poor. And those high-priced bull heads use expensive lenses made of low dispersion materials, so the photos taken are pure and clear.

Dispersion is an optical phenomenon, and the phenomenon that polychromatic light is decomposed into monochromatic light to form a spectrum is called optical dispersion. Using prism or grating as "dispersion system" can realize dispersion. In addition to pure laser light sources, most light sources in nature are mixed with many different colors of light. For example, sunlight is a mixture of visible light and infrared ultraviolet light. The main reason for dispersion is that the wavelengths of different colors of light are different, and the refractive index of ordinary optical elements will change with the wavelengths of light.