Correct. ----- Original Message ----- From: "John Yeo" <jonn...@thegrid.net> To: <pinhole-discussion@p at ???????> Sent: Wednesday, December 11, 2002 2:48 PM Subject: Re: [pinhole-discussion] What is Diffraction?
> > a glass of water with a straw inside is a simple example. > > you see the straw bent but it is not. > > thats what happen with light when it changes the medium it is travelling > > (from air to water or through the glass, example). I am not sure about > > what happens with pinhole, once there is no medium change. anyone? > > I believe that is refraction, where the light bends when it goes from one > medium to another. > > An example of deffraction would be the edge of your shadow. If you look at > the edges of a shadow, you will see that it is not a distinct line, but > rather a fuzzy transition. In short, when light strikes the edge of an > object, it scatters. > > If you think of the metal around the pinhole as casting a shadow on the > film, the edge of the shadow (spot of light from the pinhole) isn't a > perfect circle because of diffraction. The edges of the spot of light are > blurry, which degrades the sharpnes of the image. > > Hope that helps, > John > > > > _______________________________________________ > Post to the list as PLAIN TEXT only - no HTML > Pinhole-Discussion mailing list > Pinhole-Discussion@p at ??????? > unsubscribe or change your account at > http://www.???????/discussion/ >
