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eschiesser
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This is a very vague question, but I hope by asking it, we can pin down an answer eventually.
In optics, there are such things as "Coherent Imaging" and "Incoherent Imaging." From what I understand, the degree of coherence has to do with the size of your Point Spread Function (PSF), a.k.a. the image of a point source a.k.a. d=1.22*wavelength/NA and the correlation of phase over many times the PSF at your image plane.
Given that understanding, what exactly would I need to know about an optical system and whatever it is imaging to determine the degree of coherence?
Lets set up an example:
We're imaging a black-white grating on the moon (avg distance 400,000 km) with a period of 1km. Let's assume that the sun is illuminating the grating, and my eye has a pupil diameter of 7mm and can resolve 2 point sources separated by 1 minute of arc, and I am imaging with a telescope. Is this coherent or incoherent? Do I need any other information to tell?
The way I've set it up, this would seem incoherent. But on what grounds? How can I tell? What determines coherence!?
Anything and everything appreciated.
-Eric
In optics, there are such things as "Coherent Imaging" and "Incoherent Imaging." From what I understand, the degree of coherence has to do with the size of your Point Spread Function (PSF), a.k.a. the image of a point source a.k.a. d=1.22*wavelength/NA and the correlation of phase over many times the PSF at your image plane.
Given that understanding, what exactly would I need to know about an optical system and whatever it is imaging to determine the degree of coherence?
Lets set up an example:
We're imaging a black-white grating on the moon (avg distance 400,000 km) with a period of 1km. Let's assume that the sun is illuminating the grating, and my eye has a pupil diameter of 7mm and can resolve 2 point sources separated by 1 minute of arc, and I am imaging with a telescope. Is this coherent or incoherent? Do I need any other information to tell?
The way I've set it up, this would seem incoherent. But on what grounds? How can I tell? What determines coherence!?
Anything and everything appreciated.
-Eric