The camera obscura is the predecessor of the modern camera. It is the simplest optical device that allows you to get an image on the screen, and translated from Latin means "dark room".
Create a pinhole camera
A pinhole camera is an optical device. It consists of an opaque box, on one side of which there is a hole for light rays to enter, and a screen on the opposite side. The screen can be a white sheet of paper or frosted glass. The rays pass through the hole and form an inverted image on the screen.
The first obscura were stationary and the creation of portable devices was a big step forward. The fixed cells were small darkened rooms with a hole in the wall and a white screen on the opposite side. Wearable cameras made it possible to work with them more productively. At first, these were dark tents that could rotate so that scientists could observe the starry sky, the sun. Collapsible cameras appeared a little later. They were very cumbersome, but it became possible to expand the scope of their application.
The first mention of the phenomenon that underlies the work of the camera obscura dates back to the 5th century BC. The Chinese philosopher Mao Tzu described in his writings how he had to observe something interesting and mysterious. An image appears on the wall of a dark room if a light beam enters the window. Aristotle also wrote about this.
In the 10th century, the Arab scientist Ibn Alhazen explained this phenomenon and created an observation tent in the form of a camera obscura. Such a device was needed to observe the starry sky and solar eclipses. At first, only astronomers used it, but several centuries later, Leonardo da Vinci found the use of the camera in painting. In 1950, an Italian physicist equipped the camera with a lens, and a little later, scientists suggested defragmenting the lens.
Despite the fact that initially the camera obscura was exclusively an instrument of astronomers, artists began to use it actively. They used it to create portraits, landscape paintings, getting the desired image on the wall and outlining the contours with charcoal, paints and other materials, and then completing the details. This greatly facilitated their work. It has already been proven that many of the brilliant paintings of great artists, striking in the abundance of details, were painted with the use of obscura.
At some point, physicists thought about how to fix the image on the screen. So, on the basis of an old device, the first camera was created.
The principle of the camera obscura
The principle of operation of the device is quite simple. The rays entering the hole reach the screen or paper board and "paint" on it an inverted image of the object that is in front of the front side of the device. The greater the distance between the hole and the screen, the larger the size of the resulting picture.
The quality of the image on the screen or paper depends on the diameter of the hole. The smaller it is, the sharper the picture is, but at the same time it is darker. You can make the image brighter by increasing the diameter of the window, but in this case, stray rays will enter the camera and the image will be blurred.
The dark room in the hole in the wall is a fixed camera obscura. The human eyes are arranged according to the same principle. To see more sharply and clearly, people are helped by the amplification of the optical scheme by the lens and the eyeball.
Advanced and modern pinhole cameras
Since the creation of the camera obscura, the device has been constantly improved and continues to be improved at the present time. All modern cameras can be called an improved modification of the camera obscura. They work on the same principle.
In 1550, Italian scientists proposed inserting a lens into the device. This allowed for a sharper image and controlled sharpness. The rear wall of the obscura was made movable.
In 1686, Johannes Zahn upgraded the device to create a portable camera. The image on her screen was no longer upside down. This was achieved through the use of mirrors. The scientist positioned them at an angle inside the chamber. Obscura has become much more convenient to use.
The obscura, designed by a French physicist, was a tetrahedral pyramid. It consisted of four slats. at the top of the rail they were connected with couplings. As a screen, the scientist suggested using a white background, on which they subsequently began to apply special fixing reagents.
Using the camera in real life
Knowing the principle of operation of a pinhole camera, you can use this phenomenon to create primitive cameras and even home theaters. In ancient times, people drilled a small hole in the walls facing the street, and had the opportunity to observe on the opposite wall what was happening outside the window. When there were no TVs in the houses, it was quite interesting entertainment.
Nowadays, this has lost its relevance, but many novice artists use this technique. To paint the walls, to depict a beautiful landscape on them, you can create an impromptu camera by draping the curtains and making a small hole in the dense material. Using large lenses, you can flip the image and sketch, and then finalize the picture.
Modern photographers use steno to create interesting work. It is a modern modification of the pinhole camera. Outwardly, it looks like a regular camera, but the lens is covered with a cover, in which a small hole is drilled. The photographs are unusual, with a clearly defined perspective line.
Currently, primitive pinhole cameras are used to:
- science and education;
- obtaining unusual photographs;
- demonstrations.
In some cities, cameras are installed in museums or even in open areas so that people can see with their own eyes what their ancestors used, and also understand how this invention works.
How to make a camera obscura yourself
Even people who are not related to photography and painting can experiment with light and images. To create a primitive obscura camera, you need to take a matchbox, make a small hole in it, and attach photographic paper to the opposite side inner part. The boxes must be placed on a windowsill or in an open area for 4-6 hours, after which it will be possible to open it and evaluate the result. The image will appear on the photo paper. By the same principle, a camera obscura can be made from a tea tin can, from a shoe box.
In this experiment, you can also use photographic film, but not overexposed. The diameter of the hole in the box should be very small. If you make it larger, the experiment will fail because the film is blown out.
Photo enthusiasts can make a more complex camera model. This will require:
- camera body cover;
- a square piece of aluminum (can be cut from a beer can);
- needle;
- sandpaper;
- electrical tape in black.
A hole must be drilled in the camera body cover. The hole diameter is 5 mm. All irregularities should be smoothed out with emery paper.
You also need to make a hole in the piece of aluminum. Next, you need to connect the aluminum square to the body. It is convenient to do this with electrical tape. It is important that the holes match. Then you need to attach the cap to the lens and start shooting. Since the aperture in this case will be closed as much as possible, it is recommended to use a tripod. This will make the pictures clearer.
