29 Jun Pinhole Camera to Venus
On June 5, Venus passed between the Earth the sun causing a rare celestial event. This event caught some of us at Key Tech by surprise, and at the same time we felt the need to see this event that will not happen again until 2125. As such, we spent part of our afternoon trying to devise ways to stare at the sun without hurting our eyes, and the best option we found was to build ourselves a pinhole camera.
The basic theory behind a pinhole camera is well document (See Wikipedia here). With a very small hole, you can let in a very small amount of light, thus offsetting aiming the camera directly at the sun. But for the images you capture to be clear, the hole must be very, very small. For Key Tech, this is a perfect engineering challenge. What do we have lying around that can make an extremely small hole that is still round? Soon a competition was in order, who could find the best solution to this challenge.
The simple answer is to find the smallest drill bit possible, which around our office is 18mils. But this hole proved too large for clear images. A better option was to use copper tape which is fully opaque, and poke a very small hole through the center. Keith and Frank got into a bit of a competition finding the smallest objects to poke holes, and in the end they both did a good job at creating holes in the range of 5-7mils. The picture below shows the very small holes on the camera lens covers.
We put our pinhole camera to the test, and found that it worked better than expected. Images came out a bit blurry, but the concept was definition working. The image below shows Keith Frank and I with our makeshift camera. Unfortunately, when we aimed it at the sun we found that without magnification it was impossible to see the small black dot that was Venus in the middle of a bright sun. But the pinhole camera was a success none the less.
As for the transit of Venus, as it turns out the local Maryland Science Center was giving out special viewing glasses that allowed direct viewing of the event. Those, combined with a zoom lens on one of our cameras produced the images below, which captures the transit pretty well. In the end we ended up with two successful projects, both capturing the transit on camera, and also overcoming the challenges of building a pinhole camera with nothing but the basic tools we had lying around. Check out the images below to see our success on both accounts!