Wednesday, April 23, 2008

Camera Obscura

So Rob Newell, James Chutter and I decided to build a camera obscura the other day at DDB's offices, where I'm currently working on a project. Actually, it was really Rob's idea, and I was just happy to be his assistant. He has so many wonderful ideas, it's probably a good thing he doesn't want to rule the world.

So we went to IGA and bought a bag of plastic bags. (enviro-no-no, but it was for the cause of science) Then we taped them to the window frames, totally blacking out the room. This was slightly more challenging than expected, but it worked reasonably well. Then we cut a small hole in the plastic bags and turned off the lights. 

What we got on the far side of the room was an inverse image of what was on the other side of the windows. We could see the traffic driving by on the street below on the ceiling above us. The clouds were on the floor. 

I think I've figured out how/why this works; normally the light entering a room is deflected from a variety of angles outside. But when it's only coming through one small hole each spot on the opposite wall is only reflecting the light from a single exterior source. So that wall only reflects the particular colour from its corresponding spot outside. It's the same way your eye works, only your eye has your brain to flip over the image.

If that doesn't make sense, you're not alone. But for me to properly explain would make this an extremely long and boring blog entry. If you're interested though, let me know in the comments section below and I'll follow up with a proper explanation.

Here's a photo from the effort. I've tried to upload others for the past 10 minutes, but Blogger is not cooperating:
Let me know if you want to see more.


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