Chromatic Aberration in Photography is an aberration of optical lenses, resulting from incident light of various wavelengths refracted at different rates. So in case of Chromatic Aberration, the practical factor is the optical lens not really the digital component. The importance of Chromatic Aberration in Digital Photography is that, Chromatic Aberration can be expected from lower end digital cameras.
Chromatic Aberration in Digital Photography
The optical defect affects adversely especially in light-dark transitions, imparting a green and red fringing (lateral chromatic aberration) and the picture looks blurred and hazy (chromatic aberration). The degree of refraction ( refractive index) by a medium of the wavelength is dependent of the on the incident light’s dispersion. Thereby is generally the short-wave light blue is affected more than long wavelength red end of spectrum. This effect inequivalent to the effect evident in the prism.
In case of a lens, this leads to different focal lengths for different wavelengths, that is, the blue component of the image is focused in front of the red component. Both due to their location on the optical axis and through the image plane of the images, which differs from each for the three primary colors. Therefore, differentiating with the chromatic aberration between an axial chromatic aberration and a lateral chromatic aberration is important. By the chromatic aberration different color edges are created before and behind the focal plane. Lateral chromatic aberration produce fringing not the radial contrast edges, the color depends on whether it is from the center of vie, a light-dark transition or a dark-light transition.
Countermeasures for Chromatic Aberration in Digital Photography
1 | Image Courtesy : ontfin.com ; Commonly seen Chromatic Aberration in low end cameras |
Practically this error needs to be optically corrected. By combining lenses of glasses of different refractive index, this error can be corrected. In addition, the primary color green is combined with the other two, and it is an apochromatic correction in that case. Thus, the lateral chromatic aberration is also corrected. It is available only at very high end expensive optical systems.
