The Camera Obscura is Mathematical Artistry

When something has as obscure a name as “camera obscura,” you’re bound to wonder what it is and what it’s used for. And unless you’re a history or film buff, you probably don’t know much about the camera obscure.
So let’s correct that with this quick lesson in one of the coolest art devices that have been mostly lost to time.
What is camera obscura?
Camera obscura is an early ancestor of the photographic camera.
A camera obscura is a device used to project an image of the outside world onto a surface inside a dark room. It is one of the earliest forms of photography and was used by artists to trace images onto canvas. The word “camera” comes from the Latin word for “room,” and “obscure” comes from the Latin word for “dark.”
The first known mention of the camera obscura was in the Chinese Mozi, a philosophical text written in the 4th century BC. In the text, Mozi describes how a convex mirror can be used to project an image of the sun onto a wall in a dark room.
The camera obscura was later described in detail by the Arab physicist Ibn al-Haytham in his Book of Optics, written in the 10th century. Ibn al-Haytham’s work was translated into Latin in the 12th century, and it is this Latin translation that was responsible for the spread of the camera obscura throughout Europe.
How the camera obscura works with spots of light
Using the art of light manipulation, the camera obscura is capable of casting or projecting an inverted image from outside of it onto an opposite wall, essentially replicating reality the way that we now use a photo camera to do, but way before those types of cameras existed.
As you can imagine, thousands of years ago, projecting a copy of reality probably looked and felt like magic. But how did Obscura boxes really work?
Well, it starts with a room, box, or tent with a small hole in one side of it. When rays of light travel through the hole, which can be thought of as a version of our modern camera lens, it refracts and reproduces the outside scene, inverted and reversed, but otherwise identical. Interestingly, this angled mirror is also similar to how the human eye perceives the world.
Creating art from a magic lantern
The camera obscura was first used for artistic purposes in the 15th century when Italian Renaissance artist Leon Battista Alberti wrote about using it to trace images. The camera obscura became increasingly popular with artists in the 16th and 17th centuries, as it allowed them to easily transfer an image onto paper.
Some art historians even claim Canaletto and Bernardo Bellotto used the camera obscura to interpret Venice and other cities too.
In the 18th century, scientists picked up where the mathematician left off and began to experiment with using the camera obscura for photography. In 1826, Joseph Nicéphore Niépce used a camera obscura to take the world’s first photograph. Niépce’s photograph was taken on a pewter plate coated with bitumen, and it took eight hours of exposure time to produce.
Despite its long history, the camera obscura is still used by artists today. Artists such as David Hockney and Chuck Close have used camera obscuras to create large-scale portraits. The camera obscura is also popular among amateur photographers and enthusiasts.
Interestingly, camera obscura became so useful as a drawing aid that many artists started to see it as a form of cheating, leading to its use being quite controversial in the art world. However, for would-be judges, it’s worth noting that turning even a traced drawing into a work of art requires skill and judgment.