There are many ways to explore and experiment using your Personal Pinhole Theater. Here are just a few:
Systematically vary the size or shape of the pinhole and note how the image changes. You can also try using two pinholes and see what happens.
Walk right in!
There are giant, walk-in camera obscuras all around the world. See if there’s one nearby that you can visit. Or create one of your own by making a Personal Pinhole Theater from a refrigerator box that’s big enough for your whole body.
Some people think that Renaissance artists used portable camera obscuras very much like your Personal Pinhole Theater to create their masterpieces. This hotly contested theory can make a great research project.
If you teach about light or photography, the Personal Pinhole Theater demonstrates a classic tradeoff in optics: balancing brightness with sharpness.
In photography, the zone in which objects will be in sharp focus is known as depth of field. The smaller the lens aperture or camera lens opening, the greater the depth of field. In other words, the more the lens opening is like a pinhole, the greater its ability to have objects at different distances simultaneously appear in focus. As the opening is made smaller, however, less light is allowed through, and you have to use a longer exposure time to compensate. To take a picture in dim light, you open the lens wider to let in more light, but in so doing you sacrifice depth of field.
This Snack can also be used to show interesting physiological properties of the eye. Your eyes can function over nine orders of magnitude of brightness. However, you might notice that it takes time for your eyes to adjust from bright surroundings to the darkness inside the box. This is called dark adaptation. It might take up to 30 minutes for your eyes to fully adapt to near darkness, allowing your eyes to be up to a million times more sensitive to light than at full daylight.
The light sensors located on the retina at the back of your eye are called rods and cones. Rods only detect light and dark (or black and white). They’re highly sensitive and can be activated by only a few photons striking them. Cones, on the other hand, sense different colors of light, and need much more light to be activated. That’s why the pinhole image projected inside your Personal Pinhole Theater is usually only seen in black and white. If you enlarge the hole, allowing more light to flood in, you can see the image in color.