Hi Hans,
Because my students don't speak much English, I teach in a very hands-on way.
I turn on a naked light bulb at one end of the studio and mark off 1m intervals along the floor from 0 to 6m I then get them to take light readings at the various distances. They chart them and then we sit and talk about the readings to see that everyone has the same result.
They notice that as the distance doubles they lose 2 stops etc.
I get them to draw a triangle (Representing the plan view of the experiment) 16cm high with a base of 16cm, and measure the base at 2cm intervals from the apex.
They measure the base at 2cm intervals from the apex and they see that as the distance from the apex doubles, so the base doubles too.
I show them the pyramid diagram and show that the light covers a greater AREA as the distance incr
eases.
If the the SIDE doubles, then the area SQUARES so we have a "SQUARED LESS LIGHT"
If the area covered at 2m is 5 m X 5m = 25 square meters, then the area covered at 4m is 10m X 10m =100 square metters (1/4 the light for 2x the distance
2 makes 1/4
or
4 makes 1/16
or
3 makes 1/9
and I say "Lets call it 1/square and say that light gets less at a rate of 1/square times the increase in distance.
Then I write out the inverse square law.
Most of them get it
h
Hans Klemmer <hansklemmer@xxxxxxx> wrote:
Jeff,I have been lurking here for a while, and sending in comments now and again. I'l l scan some of my recent LF negs. and post them when the semester quiets down. The point to my previous message is that there has been a lot of good information exchanged in this forum in the past and I am guessing that most of don't want to read personal arguments.Now, if you would like me to begin a discussion by asking a question, I will; how do the rest of the instructors in this forum teach the inverse square law to new students?Hans KlemmerCollege of DuPage
"I have discovered photography. Now I can kill myself. I have nothing else to learn."- Pablo Picasso
On Feb 5, 2006, at 7:58 PM, Jeff Spirer wrote:
Hans, you are a new name here. Where can we see your photos or read your writings, other than a post about what makes one a photo geek?At 05:41 PM 2/5/2006, you wrote:Bob & Jeff, if you two are going to argue, please email each other directly and save the rest of us the trouble of deleting your messages.Jeff SpirerPhotos: http://www.spirer.comOne People: http://www.onepeople.com/
Herschel Mair
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Head of the Department of Photography,
Higher College of Technology
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