Tag Archives: achromatic

A Simple Model for Sharpness in Digital Cameras – Polychromatic Light

We now know how to calculate the two dimensional Modulation Transfer Function of a perfect lens affected by diffraction, defocus and third order Spherical Aberration  – under monochromatic light at the given wavelength and f-number.  In digital photography however we almost never deal with light of a single wavelength.  So what effect does an illuminant with a wide spectral power distribution, going through the color filter of a typical digital camera CFA  before the sensor have on the spatial frequency responses discussed thus far?

Monochrome vs Polychromatic Light

Not much, it turns out. Continue reading A Simple Model for Sharpness in Digital Cameras – Polychromatic Light

COMBINING BAYER CFA MTF Curves – II

This is a vast and complex subject for which I do not have formal training.  In this and the previous article I present my thoughts on how MTF50 results obtained from  raw data of the four Bayer CFA channels off  a uniformly illuminated neutral target captured with a typical digital camera through the slanted edge method can be combined to provide a meaningful composite MTF50 for the imaging system as a whole1.  Corrections, suggestions and challenges are welcome. Continue reading COMBINING BAYER CFA MTF Curves – II