What is Camera Obscura?
Camera obscura, meaning “dark room” in Latin, refers to the natural optical phenomenon that occurs when an image of a scene is projected through a small hole as a reversed and inverted image on a surface opposite to the opening. The surroundings of the projected image have to be relatively dark for the image to be clear, so many historical camera obscura experiments were performed in dark spaces. The term “camera obscura” also refers to man-made constructions or devices that make use of this image reflecting principle within a box, tent, or room.
A Brief History of Camera Obscura
The origins of camera obscura are said to stem all the way back to ancient China, where the philosopher Mo-Tzu first observed the visual phenomenon in around 400 B.C. In his writings, analyzing the characteristics of optics, Mo-Tzu describes how light can bounce off a subject, for instance, off of a man, and how a small pinhole can capture the light bouncing off of this man, creating an inverse image.
Later, in the 11th century, these ancient observations were further studied and documented in the Book of Optics by Arab scientist and philosopher, Ibn al-Haytham, allowing the mathematical mechanisms behind the Camera Obscura to be known in the Middle East and across Europe.
His study of optics, and the nature in which light travels, laid the foundation for our understanding of focal points and how light refracts and intersects, creating an upside-down image. In his study of optics, Ibn al Haytham came to the conclusion that the act of seeing occurred in the brain and not in the eyes themselves, as the eyes served as a conduit to processing the light from the outside world.
Similarly, Ibn al-Haytham advanced, not only the understanding but the usage of the Camera Obscura, as he introduced the idea of projecting the play of light onto a screen. This proved to be a game-changer, allowing the light from the outside world to be contained and viewed in darkened interiors at will.
The work of Ibn al-Haytham inspired many scientists and artists during the Renaissance. Familiar with the studies of Ibn al-Haytham, Leonardo Da Vinci also tinkered with a Camera Obscura obsession. In the year 1502, in his Codex Atlanticus, Da Vinci wrote and published diagrams explaining in detail the functioning of the Camera Obscura. Tents and portable rooms were even used to capture specific landscapes.
Soon after, the Camera Obscura combined with a converging lens to turn the inverse image into an accurate right-side-up representation of the outside world. With the introduction of a converging lens, camera obscura became an even more popular artist’s tool for photo-realistic drawing and painting.
The Camera Obscura box was developed further into the photographic camera in the first half of the 19th century when camera obscura boxes were used to expose scenes to light-sensitive materials to capture and record the image.
Fast forward to today and the Camera Obscura still captivates us. Check out this exhibition which used this play of light in modern exhibition space.
How to Transform your Room into a Camera Obscura
The beauty of the Camera Obscura is its simplicity. You don’t need fancy equipment to see how it works, in fact, you just need a dark enclosed space and a small hole to see how it works for yourself!
What you’ll need
- A Room with one Window
- Thick black poster board or several large cardboard boxes. (as many as you need to cover the window and be thick enough to block all light!) —ps. fabric can also be used such as light proof curtains.
- A blank wall opposite the window. If it is not blank, you can hang a white sheet over what ever is hanging there, as this is where your image will project.
- A towel
- An empty toilet paper roll
- Scissors or Cutting Knife
Step 1: Find Your Space
You will want to use a room with a view that only has one window. Try to clear any clutter. Your image will be projected on the opposite wall so make sure it is free from hanging pictures or mirrors. If this isn’t possible, hang a white sheet on the opposite wall to use as a screen.
Step 2: Cover the Window
Next, you will need to block out all the light coming into the room. Black out the windows by covering them with a black opaque poster board or thick cardboard. Alternatively, you can use special window film material to remove all light.
Use tape to secure your covering to the window frame. Make sure the edges and corners are properly sealed.
Now, before shutting out all the light completely, cut a square hole, or save an uncovered space, out of the middle of the window about the size of the palm of your hand.
Step 3: Prepare your Pinhole
Next, take your left-over letter-size piece of cardboard or thick window covering. With the toilet paper roll or with a similarly-sized cylinder, trace and cut out a circle from the middle of the paper. The size of the hole should measure approximately between 10-15mm in diameter.
Tip: You can make several of these letter-sized pieces of cardboard with varying hole sizes to test out which yields the best results. The exact size depends on the distance between the hole and wall projection.
Reinforce the inside of your circle with duct tape. Then tape this board over your empty square on the window. Seal it well so that no light is leaking.
Step 4: Let the Magic Happen
Close your door. Also, check if light is leaking in underneath the room door, and if so, cover the gap between the door and floor with a blanket or towel.
Finally, turn off the lights! It may take a few minutes before your eyes adjust to the darkness but soon you will see the inverted projection from the outside view on the opposite wall.