I mean, dispersion matters simply because people generally don't want colored fringing and general haziness in their photos? There are two types of chromatic a

I mean, dispersion matters simply because people generally don't want colored fringing and general haziness in their photos? There are two types of chromatic aberration (CA), both caused by dispersion. * Axial: perfect focusing is impossible because different wavelengths focus at different distances. If green light is focused correctly, then red and blue light is out of focus. This affects the entire image and is very difficult to fix in post-processing. * Transverse: there's no unique image because magnification depends on wavelength. Blue light forms a slightly larger image than green, and green larger than red. This manifests as color fringing, most apparent near the edges and corners of the image, far from the optical axis. This can be alleviated algorithmically, by resizing the red and blue sub-images to match the green one.