
-----------------------------------
nobody
30 Mai 2010 21:22


-----------------------------------
Teoretic, la o diafragma mai mica, vei avea un airy disc mai mare.
In cazul Soarelui (luminozitate mare in background) treburile se schimba.

For other image forms, resolution limit also can and does deviate significantly, both, above and below the conventional limit. One example is a dark line on light background, whose diffraction image is defined with the images of the two bright edges enclosing it. These images are defined with the Edge Spread Function (ESF), whose configuration differs significantly from the PSF (FIG. 10). With its intensity drop within the main sequence being, on the other hand, quite similar to that of the PSF, resolution of this kind of detail is more likely to be limited by detector sensitivity, than by diffraction (in the sense that the intensity differential for the mid point between Gaussian images of the edges vs. intensity peaks, forms a non-zero contrast differential for any finite edge separation).

Pe de alta parte: Image of a point source on the surface of extended objects in general - with the exception of Sun -  is not detectable in amateur telescopes.


