Blurring (nonzero blob size) is not caused by the edge of the iris. It is caused by the iris' elimination of the good, far-from-the-axis rays. Larger apertures result in a larger spread in path-length differences for the various rays striking the sensor at points away from the ideal image point. This increases the destructive interference at these points, resulting in a sharper image.
Showing posts with label diffraction. Show all posts
Showing posts with label diffraction. Show all posts
Saturday, February 9, 2019
Diffraction Blur in Imaging
Because of the wave nature of light, the image of a point is not a point but a blob whose size depends on the wavelength and the f-number of the lens. In the Diffraction Blur article, I compute this blob profile, including the off-axis case.
Blurring (nonzero blob size) is not caused by the edge of the iris. It is caused by the iris' elimination of the good, far-from-the-axis rays. Larger apertures result in a larger spread in path-length differences for the various rays striking the sensor at points away from the ideal image point. This increases the destructive interference at these points, resulting in a sharper image.
Blurring (nonzero blob size) is not caused by the edge of the iris. It is caused by the iris' elimination of the good, far-from-the-axis rays. Larger apertures result in a larger spread in path-length differences for the various rays striking the sensor at points away from the ideal image point. This increases the destructive interference at these points, resulting in a sharper image.
Subscribe to:
Posts (Atom)