is it just a refelction in different direction after striking some object , or they really store the image with the object they strike. if it is so what characterisitcs of photon retain these images?
A single photon leaving the surface of an object does not, of course, carry (or “store”) an image. It carries only its energy and momentum. If the momentum happens to be in the direction of a lens (of an eye or a camera), it interacts with the material of the lens by a complex process of absorbtion and emission called “refraction”, the net effect of which is that photons exiting the lens strike a photo-sensitive material (eg., a retina, a camera film, a screen...).
At any instant an enormous number of the photons leaving the various points on the object will be be travelling towards the lens. The net effect is that the points of the light-sensitive surface are absorbing photons, each carrying energy, which corresponds to frequency (E = hν), and the rate at which they are received corresponds to intensity. The distribution of frequencies and intensities over the surface of the light-sensitive layer constitutes the image.
A single photon leaving the surface of an object does not, of course, carry (or “store”) an image. It carries only its energy and momentum. If the momentum happens to be in the direction of a lens (of an eye or a camera), it interacts with the material of the lens by a complex process of absorbtion and emission called “refraction”, the net effect of which is that photons exiting the lens strike a photo-sensitive material (eg., a retina, a camera film, a screen...).
At any instant an enormous number of the photons leaving the various points on the object will be be travelling towards the lens. The net effect is that the points of the light-sensitive surface are absorbing photons, each carrying energy, which corresponds to frequency (E = hν), and the rate at which they are received corresponds to intensity. The distribution of frequencies and intensities over the surface of the light-sensitive layer constitutes the image.
Inside a traditional copy machine, or laser printer, the light sensitive surface (i.e. the white sheet of paper) is electrically charged. Where the light intensity is high, the electrons will be absorbed. In dark areas the electrons will remain. This is how the black letters appear on a printed sheet of paper from a laser printer.
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