frankqt
Member level 4
Assume two systems: (See below)
In the first one there is no lens, just a simple detector. In the second case there is a lens system with a particular focal length and f#. I am trying to see what is the impact of lens in terms of total photons hitting the detector.
In the first system there is no lens so the total number of photons is proportional to the area of the detector. In the second system there is a lens I assume the number of photons hitting the detector is different. There are optical losses and also size of the aperture of the lens makes a difference.
So, I am trying to gauge what is the difference?
Assuming optical transmission is T, the lens aperture area is A, detector area is D. My guess is the number of photons difference is as follows:
Assume total number of photons for detector only case is X, and Y for with the lens. My guess is
Y= T*X*A/D
Is this correct? Does focal length or f# make any difference?
In the first one there is no lens, just a simple detector. In the second case there is a lens system with a particular focal length and f#. I am trying to see what is the impact of lens in terms of total photons hitting the detector.
In the first system there is no lens so the total number of photons is proportional to the area of the detector. In the second system there is a lens I assume the number of photons hitting the detector is different. There are optical losses and also size of the aperture of the lens makes a difference.
So, I am trying to gauge what is the difference?
Assuming optical transmission is T, the lens aperture area is A, detector area is D. My guess is the number of photons difference is as follows:
Assume total number of photons for detector only case is X, and Y for with the lens. My guess is
Y= T*X*A/D
Is this correct? Does focal length or f# make any difference?