- #1
fisico30
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Dear Forum,
Consider an object, illuminated with coherent light, that is located very far away from a positive lens.
The object is considered to be at "optical infinity" (its distance is simply very large compared to the focal length of the lens).
In that case, the image of the object (real, small, inverted) will form on the back focal plane of the lens (to be picky, on a plane that is infinitesimally close to the focal plane).
Here my confusion: what forms on the back focal plane? The image of the object or the modulus squared of the FT of the object?
It would seem that both FT and image are in the same plane or that the FT is within the depth of focus...
thanks
fisico30
Consider an object, illuminated with coherent light, that is located very far away from a positive lens.
The object is considered to be at "optical infinity" (its distance is simply very large compared to the focal length of the lens).
In that case, the image of the object (real, small, inverted) will form on the back focal plane of the lens (to be picky, on a plane that is infinitesimally close to the focal plane).
Here my confusion: what forms on the back focal plane? The image of the object or the modulus squared of the FT of the object?
It would seem that both FT and image are in the same plane or that the FT is within the depth of focus...
thanks
fisico30