Friday, June 25, 2010

Camera Obscura

On Father's Day we (okay, the boys and Jerry - I took pictures!) built a camera obscura. Here is a link that will tell you how it works. What it is, or was in our case, was a cardboard box with a hole drilled into it. Tom had told us about one of his classes in Arlington when they had covered all the windows in the classroom until it was completely dark and then put a pinhole in one of the window coverings. The Arlington streets and skyline were then projected onto the back wall of the darkened classroom, upside down. He said they watched people walking by, cars and clouds - all upside down. We tried first to put a piece of blueprint paper onto the back wall of the closed box but no image came out. We discovered that would take a LONG time for the exposure to put an image on the paper.

Jerry is closing his office in Delaware and as things were being moved out of the office, an old blueprint machine was about to be thrown away. More about the Delaware office in a future post, though. Jerry and I decided that we wanted to play around with the machine before we threw it away, and there was an unopened package of blueprint paper too, so the boys and I started doing some experimentation to see what we could do with it. It doesn't take much to amuse us, as my readers already know!

We tried using the paper as sun paper - you know, the kind you used to use as a kid when you would lay rocks and such on it and leave it out in the sun and the images would appear in contrast on the paper? We left ours in the sun too long. Turns out you only have to expose it for a few short minutes, but that diazo (blueprint) paper also needs a chemical reaction to finish developing, like a photo. That's why there's ammonia in a blueprint machine to finish the development process.

Later on after taking the box back in the garage, Andy got inside it to see if there would be an image projected onto the back wall of the box. After a few minutes of his eyes adjusting to the dark, he was able to see our driveway projected upside down on the back of the box. Then a neighbor walked over to visit and Andy saw him approach - upside down - on the back wall of the box. As if the neighbors needed further confirmation that we weren't wrapped too tight, having our son in a cardboard box on a 90-degree day confirmed it!

We half-celebrated Father's Day last week. We'll be doing the second half this weekend. Andy's gift to Jerry ended up being delayed in shipping with UPS and didn't arrive in time, so we get to celebrate twice. I'll post about Jerry's gift after he actually gets it, if I get a chance. If not, have a great weekend, y'all!

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