The camera obscura can be compared to a very rudimentary camera.
Light travels in a straight line. There are several examples that prove this principle, such as observing the path taken by the light coming out of a film projector. Another example is the camera obscura, which consists of a box with a hole in one of the sides (as if it were a very rudimentary camera). This hole allows light to enter by projecting an image into the chamber on the face opposite the hole.
The camera pictured above is an improved hole camera obscura as it uses a lens to obtain better quality images.
The functioning of an orifice camera obscura is directly linked to the principle of rectilinear propagation of light, as shown in Figure 1.
By placing an object (o) in front of the hole, its image (i) will appear inverted on the screen. The face of the background allows the observer to see the occurrence of this image, as it is a tracing paper, which will be smaller and smaller the further away the object (o) is found.
o is the length of the object placed in front of the camera;
i is the length of the image formed on one face of the camera;
p is the distance from the object to the camera;
p’ is the depth of the chamber.
