The only way we can see through a wiindow is through the fact that the photons intefere both constructively and destructively in just right way. The photons striking our retina are not the ones hitting the outside of the window pane! dan c. At 06:15 PM 24-10-02 +0100, Chris wrote: >I think there is a delay that could be minutes from the time of absorption >to the time of re-emission as a statistical random manner in time and >direction, thus preventing constructive interference to make a forward beam >in the case of light absorbed by pigment. > >Chris. > >-----Original Message----- >From: owner-photoforum@listserver.isc.rit.edu >[mailto:owner-photoforum@listserver.isc.rit.edu]On Behalf Of Dan C >Sent: 24 October 2002 15:47 >To: List for Photo/Imaging Educators - Professionals - Students >Subject: RE: Just how do filters work? > > >It's actually much more complicated than that. Even clear glass absorbs >all of the light that hits it. No photon actually gets all the way >through a glass filter unimpeded. The photons are absorbed and remitted >(in all directions) continually by all of the molecules that make up the >glass. It is just by a miracle of optical physics (and very complicated >mathematics!) that the re-emitted photons both constructively and >destructively interfere with one another in just the right way so that the >final outcome is an apparently identical bean of light exiting the sheet of >glass (or filter). > >Look up "Extinction Theorem" in an adanced text on Optics, such as the one >by Born and Wolf, if you really want the gory details. > >dan c. > > > >At 06:08 PM 23-10-02 +0100, Chris wrote: >>The filter absorbs light of the unwanted wavelength. >[snip] > > > >
