Before revision: Relationship with other functions in optics The complex pupil function can be written as the product of two real functions: , where is the phase change (in radians) introduced by the optics, or the surrounding medium.
After revision: Relationship with other functions in optics The complex pupil function can be written in polar coordinates using two real functions: , where is the phase change (in radians) introduced by the optics, or the surrounding medium.