It is interesting to note the human ability to recognize depth or to make an initial judgment about how far away an object is. Even though the image projected onto the retina of our eyes is flat, we can see in three dimensions (depth, height and width). Analyzing the figure above we can say that a flat image does not provide information in three dimensions correctly. The figure drawn by Escher shows a 3D situation placed on a flat screen. This image confuses our brain.
Trying to understand the image that is received by both eyes, our brain is responsible for providing the sense of depth we have. In this way, we can say that each eye observes a scene from a slightly different point of view, and sends this information to the brain. The brain itself forms the three-dimensional image of the two images sent by the eyes.
This fact is used to make a three-dimensional photograph, in which two photos of a scene from two different positions are taken. If we look at each of the photos with a different eye, we have the feeling that we are seeing a three-dimensional scene. In addition, several other elements contribute to our three-dimensional perception.
Do not stop now... There's more after the advertising ;)
Thus, the apparent movement of one object in relation to another, when the head moves, the relative size of objects and our prior knowledge of the environment around us are information we use to "assemble" the vision 3D.
The view we see on computer monitor screens and television screens is not a three-dimensional view, because the image is projected onto a flat screen. In these situations, only the size of the objects and their relative movement give us the idea of depth.
By Domitiano Marques
Graduated in Physics
Brazil School Team
Would you like to reference this text in a school or academic work? Look:
SILVA, Domitiano Correa Marques da. "The depth we see"; Brazil School. Available in: https://brasilescola.uol.com.br/fisica/a-profundidade-que-enxergamos.htm. Accessed on June 27, 2021.
