Re: [Cameramakers] science project

[John Yeo]

How about making a box viewer (list - is there a better name for what i'm describing?) to illustrate how a lens works.  Have two cardboard boxes that slide into each other - the first having one open side, and the second having an open side, and a side covered by wax paper, and maybe some extra flaps to keep outside light off the waxed paper (so you would be able to see the image on the wax paper better).  Use black duct tape or electrical tape to put the boxes together to keep out stray light that will make the image less visible.    For a lens, she can tape a lens from a pair of reading glasses over a hole in the front of the first box.  Make the hole as large as possible and use the widest reading glasses lens you can find for the brightest image on the waxed paper.    As for a lens, I'd suggest popping the lens out of a pair of reading glasses.  With reading glass lenses, the focal length in millimeters (the distance from the lens to the waxed paper) will be 1000/magnification.  The magnification will hopefully be listed on the reading glasses like "2.5x".  If you can't find the magnification on the glasses, you can focus an image of the sun on the ground (like frying bugs with a magnifying glass).  When you get the brightest spot on the ground, measure the distance from the lens to the ground, and that will be the approximate focal length.    When everything is put together, she can take the box outside, point the lens at objects, and will see the object, upside down on the waxed paper.  That's pretty much how a camera works.    I'm guessing it's more of a "demonstrate a scientific principle" than an actual experiment, so this should work pretty well.  Maybe in the display, she could set up the box, pointed at a lightbulb, and an image of the lightbulb will be visible on the waxed paper.   I drew a quick sketch of what I'm talking about (hopefully that will clarify my vague description) and put it up at http://www.enteric.org/project.jpg (55kb   Hope this helps, John http://www.enteric.org/   ----- Original Message ----- From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Tuesday, March 18, 2003 7:03 AM Subject: [Cameramakers] science project My first grader has a science project coming up soon, she is fasinated with how a camera works, would it be possible to send us some information about the making of a camera, and even try to build a model of one. Thank you so much for any help you can offer us.                                                                                           Laura Coolberth                                                                                            P.O. BOX 195                                                                                            Hill, N.H. 03243