ImagingPath.entrancePupil

raytracing.ImagingPath.entrancePupil(self)

The entrance pupil is the image of the aperture stop as seen from the object. To obtain this image, we simply need to know the transfer matrix to the aperture stop, then find the “backward” conjugate, which means finding the position of the “image” (the entrance pupil) that would lead to the “object” (aperture stop) at the end of the transfer matrix. All the terminology is such that it assumes the “object” is at the front and the “image” is at the back, so we need to invert the magnification.

Returns:

entrancePupil – the position of the pupil relative to input reference plane (positive means to the right) and its diameter.

Return type:

(float,float)

Examples

>>> path = ImagingPath() # define an imaging path
>>> path.objectHeight=6
>>> # use append() to add elements to the imaging path
>>> path.append(Space(d=20))
>>> path.append(Lens(f=20,diameter=5,label="f=20"))
>>> path.append(Space(d=30))
>>> path.append(Lens(f=10,diameter=10,label="f=10"))
>>> path.append(Space(d=10))
>>> print('The (position,diameter) of entrance pupil:', path.entrancePupil())
The (position,diameter) of entrance pupil: Stop(z=20.0, diameter=5.0)