Lenses and Image Formation

Everyone was on lenses today and the patterns of image formation as you move an object in respect to the position of the lens. B, E and F Blocks reviewed their ray diagrams before looking at converging and diverging lenses, in terms of image formation, and found that for converging lenses, as you approach the lens the image gets larger and farther from the lens (while remaining real) until you reach the focal point. At the focal point the image forms at infinity (which was why E and F Blocks couldn't get a clear image of their object on their screen in lab) and within the focal length, the image gets smaller and closer to the lens as the object approaches the lens and are now virtual. The diverging lens is a simpler beast - all of the images are virtual, upright, smaller than the object and form within the focal length for any object position. We'll go over your problem-solving homework tomorrow before taking a look at total internal reflection. Well, E and F Blocks will do that while B Block works on their laboratory exercise.

C Block did work on their laboratory exercise today to examine patters to image formation by converging lenses and how measuring light divergence can let someone determine the focal length of a diverging lens. Have your lab questions/graph ready tomorrow so we can review these ideas in class.