Recent content by John_H

Thank you again for your patience in working through this. I agree that it seems like a trivial distinction, but it is helpful to me, in trying to understand this, to establish that the focal plane does not contain an image; and that the focal plane and the image plane are two different things...

Thank you for your counsel on this. The scissoring of the optical axis and principal ray is very good. It is clear that if the object has extent, the image must also have extent. No question here. It must be a problem with how words are used. The problem words are “focal plane” and...

Thank you for your help. I sketched the Halliday & Resnick drawing and pulled lines as you have suggested. It basically seems to show that the centerline/symmetrical picture is the same in principle as the one usually presented, with objects and images arranged to stand on, or hang down...

Still trying to hammer through to a clear understanding of this thing. Here is where I am. It seems to me that most of the time, and for most objects, there has to be some finite distance between the focal point and the image point. The rays converging from the lens should crossover at the...

Thank you for your help on this. Your analysis makes excellent sense but if the focal point is that far back along the axis of the lens, then where should the image form? Here are a couple of additional pictures. (I have collected several of these, trying to puzzle it out). In one...

Here is a typical photo of imaging in the eye. The bright point on the retina is called out, in a book on the biology of vision, as the focal point. I am pretty sure the book is wrong, and that this is NOT the rear focal point. The rear focal point would be somewhere closer to the back surface...

forward and reverse transforms, general form Thank you for your reply. To clarify the forward and reverse tranform procedures, here is an excerpt from Wikipedia's treatment.

I collected some links that seem to pertain. http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/oilfilm.html#c1 http://www.reindeergraphics.com/index.php?option=com_content&task=view&id=212&Itemid=158 http://www.ph.tn.tudelft.nl/Courses/FIP/noframes/fip-Properti-2.html At the...

Here is one -- pattern. I guess the problem could be cleaned up and simplified if we dispense with the water and use wet pavement, as in this photo. In this pattern, the surface is solid, all the light is arriving from the "upper world" and you get rid of the problem of light reflected from...

Thank you for your insights on this. Suppose our kitchen table has a double glass top. Here and there it produces Newton's rings type interference patterns. I understand that by reverse transforming an interference pattern you can recover an image. If I were to somehow do this...