The notebook cover is considered a translucent medium, as we cannot clearly see the image contained in the notebook.
We are able to see light through air and a vacuum because these media are considered to be transparent media . Materials such as clear plastic and glass, from which many materials are made, are also called transparent. However, when looking through some glasses, we will not always be able to see completely clear images. Therefore, these materials are considered, from an optical point of view, translucent media.
The vast majority of materials around us do not allow light to pass through. See the figure above, in which we can see that, when falling on such materials, the light is reflected in all directions, which is why we can see all objects from different positions, but this will only happen as long as there is adequate lighting.
Other objects or materials, such as film and photographic paper, plant leaves, and dark-colored objects, including black, can absorb at least some of the light that falls on them. Because they have this characteristic, they are called absorbing means .
Although light can interact with the materials it comes in contact with, it does not interact with itself. This can be verified by placing one flashlight in front of another and turning both on. The light coming from one does not change the light from the other – there is an independence of propagation .