My student teacher, Matt Dailey and I didn't know if this lesson was going to blow up in our faces but I decided that regardless of the outcome, it was going to be a great teaching/learning moment for everyone involved and it didn't disappoint. We booked a small room in our local library that is attached and shared by my school. We needed a room that we could have access to for the entire day (although a few days would have been nice). We began to paper the windows using roofing paper so as to create a light proof environment to create a camera obscura. Originally I planned to do this in warmer weather, but winter hasn't retreated as in past years at this time. The windows frames of the room are made out of aluminium and proved to be a bit tricky as the duct tape kept releasing due to the cold temperature. Regardless, with almost a full roll of roofing paper and 3 rolls of duct tape, we managed to create a light proof environment.
|The covering of the windows.|
The addition of a disposable aluminum pizza tray was added to act as a lens. Previously, a variety of holes were created in the plate and each hole was individually covered with a piece of electrical tape to allow us to discover the correct aperture for the room size. The plate lens was mounted in a central position of the chosen window after cutting an opening in the roofing paper cover.
|Plate lens before openings were covered.|
|View from lens|
The window was chosen for both its view and location of a wall of cupboards on the opposite side. In order to provide a smooth light surface to project the image on, a large white background was added in front of the wall of cupboards. I'm lucky that I happen to use lighting stands and large rolls of paper as part of my classroom studio, but a bed sheet or tablecloth would definitely suffice. The leftover roll of roofing paper was placed by the door to block out any light that would come under the door.
Now that I've described the process for building a camera obscura--which between the two of us took approximately an hour to do, the real teaching/learning moments began.
As my grade 11 students arrived for class, I explained to them that we didn't really know how today's lesson was going to go. I knew that it was going to go either one of two ways: it was going to be a moment of awesomeness or it was going to blow up in our faces and I was okay with that. I watch the expression on my students' faces change in that moment: their teacher had just told them that she didn't know if something was going to work, but but was willing to lose face in front of a bunch of teenagers. I went on to remind the students that throughout the course I have been repeating my classroom mantra, "through failure, you will learn." I explained that there were so many things that could go wrong: in actuality the weather wasn't cooperating as it had started to rain and the tape was having difficulty sticking to the cold aluminum window frames. The opportunity was worth the risk as they were going to experience what Mo Ti had in 5000 BC as well as the countless scientists, explorers and and artists who had used this tool in their own projects. Regardless, it would require cooperation and teamwork for it to work. We quickly made our way down to the library and filed into the room. The first activity that the students were asked to do was to assess the room and any issues that it may have. Items were moved from the floor and a missed window in the door itself was quickly covered. Students chatted and joked as they sat on the floor. The door was closed, the roll of roofing paper was placed in front of the bottom of the door and the lights were turned off. At first the students giggled a bit about sitting in a dark room with their teachers, but then I directed them to carefully watch the white backdrop as their pupils adjusted. I have to admit that I was holding my breath at that moment. I frantically began to think of possible contingencies plans to implement if the lesson failed, but then I began to notice the faint appearance of upside down tree branches...
|30 second exposure with overcast skies|
|30 second exposure when the skies cleared|
As I pointed out their location, students began to say that they couldn't see them, but then it was like a collective light switch was turn on and the gasps of surprise occurred across the room. I began to cheer that we had created a camera obscura as the snow, road and other trees became more visible. At this point the entire class began to cheer and applaud--all for an ancient form of technology that requires no batteries. I reminded the students how this would relate to all of the science and physics lessons they had received on optics, how Joseph Petzval's theory guides the diameter of the lens, how the explorers made the incredible first maps with extraordinary accuracy and how artists adopted this tool that gave birth to the realism period. The conversation quickly grew and the students became more excited as they connected how this room related to so many of their other courses. At one point, one of the students actually shouted, "I love science."
In that moment, I wish the science department could have been there and the math department too as other students began to talk about how they had learned about Petzval in math class. It truly was a moment of connected learning. While everyone was busily chatting away about the experiment, the rain stopped and the sky became a little brighter. Although the image was still rather dim, it did become brighter and more visible. I picked up a piece of white bristol board to show the effect of depth of field or how close the screen must be towards the lens to created a sharper image. The students were amazed at how sharp the image became as I got closer. One student volunteered to run outside of the window so that everyone to watch him appear. We watched as he suddenly appeared to be dancing on the ceiling. Nobody really wanted to leave the room but once we returned to the classroom, a class discussion about the evolution of technology continued. We began to talk about the importance of understanding both new and old technology as technological studies students and how this allows us to differentiate and evaluate technology in order to choose the best one at any given time.
A week later, students were still discussing the experience.
My grade 10s are currently in their darkroom unit and as they watched their pinhole negatives develop in the developing tray that same wonder occurred. I also noticed that students had a better understanding why their images didn't work and what modification were required to the cameras they had created. On a recent field trip, my grade 11s asked if I was planning on building another camera obscura. When I asked if they thought it was a good idea and did they learn something from it, they enthusiastically said yes....and the conversation continued on the bus. I said that next time I will be covering all of the walls so that they could experience the panoramic effect that occurs.
I should also note that other teachers and students came down to experience the room first hand. Our acting principal actually sat with my grade 10s and other teachers and students came after school. The room was busy for an hour after the final bell on a Friday. Although it didn't work out for this semester, science students were going to utilize the room for their optics unit, art students were going to use tracings from it and other subjects were going to use it in their own related units.
Such a simple, cheap idea with incredible results; I hope you build your own camera obscura room with your students.
If you don't have access to a room with a window, try to find some old family size canvas tents that you can create an opening in. You may need to build a tent in a tent and then place some dark tarps/cloths on top but it can have the same results. The importance is using materials to create that light proof environment. Your lens can still be attached with duct tape; I would also recommend using a drill to create your holes and sanding them with ultra fine sandpaper for better results.