If you exclude virtual images from your allowed vocabulary you cannot
discuss (or even recognize the existence of) many intermediate virtual
images inside an optical system. The human eye is not always the device
to which a particular image is presented.
However, the point that the eye finally constructs a real image should be
made to every optics class.
Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net http://www.velocity.net/~trebor
----- Original Message -----
From: "Kossom" <MKossover@NEWMANSCHOOL.ORG>
To: <PHYS-L@lists.nau.edu>
Sent: Tuesday, April 30, 2002 11:04 AM
Subject: Re: Test Writing
. . .
A better question that gets at the difference between real and virtual
images (a topic that I avoid since I don't believe in virtual images, see
below) might ask, "Explain the difference in these two situations. (a) A
slide projector creates an image on the wall that everyone can see. Each
person is asked to draw a picture of the image. Everyone's picture looks
nearly the same. (b) A person looks through a magnifying glass at a stamp.
Another person looks over the shoulder of the first person. Each person
draws a picture of what they see. The two pictures are not the same."
----
Instead of talking about virtual/real images, I only discuss the images
made
on the retina. They are always real. We look at how lenses change the
angles
of the incoming rays on the lens.