Pinhole Cameras

Pinhole Cameras

The Pinhole camera was the first device that can truly be called a “camera” as we know it. It works on exactly the same principle that the human eye does, only much simpler. It consists simply of a box with a tiny hole in one side. Light enters that tiny hole, much as it enters the pupil of our eye, and that light is projected onto the opposite side of the box, upside-down, just as it is projected upside-down on the inside of the retina on the back of our eyes. Unlike the eye, however, there is no lens to focus the camera’s picture on objects closer or father away, and there is no mechanical “cornea” that can regulate the amount of light that enters, so pinhole cameras are only able to take clear photographs from a set distance in a decent amount of light. As the camera only lets light enter via a pinhole, it takes much longer for the light to expose the film within. It can take as little time as five seconds or as much as several hours, or even a few days, depending on the levels of light.

History Of The Pinhole Camera

The pinhole camera was actually first theorized by two separate cultures at approximately the same time. In the fifth century BC, Greek philosophers such as Aristotle and mathematicians like Euclid noted how images can be projected through small openings, such as between the reeds of a wicker basket or the leaves on a tree. Simultaneously, the Chinese philosopher Mo Jing wrote a theory of an “image forming through a pinhole.” Then, fifteen hundred years later, the pinhole camera was again developed simultaneously by two separate cultures. The mathematician, engineer and physicist Ibn al-Haitham built a pinhole camera in the 10th century Muslim world, while Song Dynasty scientist Shen Kuo constructed one at the same time in China. Both are today regarded as the inventers of the pinhole camera.

How To Make A Pinhole Camera

It’s actually very simple to make a pinhole camera. All that you really need is a container of the right dimensions with a sheet of photographic film on the inside, a small pinhole in the opposite side and a flap that can cover and uncover the hole. For the best quality pictures, you need to be almost microscopically precise in the size of the pinhole. To determine the size of the pinhole, simply take the length from the hole to the film and multiply that by the wavelength of light (.00055 mm), then multiply the square root of that by 1.9. So, if there’s 5 centimeters from the film to the hole, the hole should be .32 mm across.