For complex reasons to do with light wavelength and better focus, this allows more information to be crammed on to a disc, resulting in better picture and sound.

Its spectrum then gradually decreases as light wavelength increases.

Color perception appears to be independent of light wavelength.

Similarly, the closer the particle size to the light wavelength (100-1000 nm for visible light) and the more irregular the surface, the larger the degree of opacification.

The type of atoms present in a sample, or the amount of atoms present in a sample can be deduced from measuring these changes in light wavelength and light intensity.