Cardboard and Christmas Present Camera

The Experiment that Started the Experiment Holding a piece of scrap-paper in one hand, the ball resting on a table, and snapping a picture I suddenly become interested in spherical lenses. I remember that some of the earliest microscopes (from the 1600’s, I think) were made with polished balls of glass. I decide not to look anything up on the internet until after I try building a camera using this ball as a lens.

First Sketch Ball, box, viewscreen, and a hole to put the camera lens through.

Second Sketch Putting the parts in relation to each other helps me think through the construction and builds a more detailed model in my head.

Precision Layout I mark and cut crude holes on both ends of the box. Later I will put more precisely cut pieces of cardboard over these holes.

Making the Imaging Screen After trying various materials readily at hand, I settle on tissue-paper (which keeps the Christmas theme going). The cardboard frame is cut slightly wider than the box so that it will make a gentle arc when it presses against the sides – this will (hopefully) more closely match the focal arc of the ball and keep the screen in place.

Assemblage Putting all the parts together (using mostly gravity), the camera starts to take shape. The ball is so much heavier than the box, I had to hot-glue a piece of plywood to the box to create a sturdy support.

First Image I neglected to account for the minimum focal distance of the camera, as a result the camera must be outside the box in order to actually focus. But, as we can see from the upside-down image of my yard, the ball is working as a lens. Notes for next iteration: longer box, put the ball inside the box to reduce intrusion of light from the sides, different viewscreen material (possibly sanded plastic from discarded packaging).