The camera obscura can be compared to a very rudimentary camera.
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.