Unique camera to see the world the way birds do

Human colour vision is based on three primary colours: red, green and blue. The colour vision of birds is based on the same three colours – but also ultraviolet. Biologists at Lund University in Sweden have shown that the fourth primary colour of birds, ultraviolet, means that they see the world in a completely different way.
This was achieved with the help of a unique camera and advanced calculations. The camera was designed within the Lund Vision Group and equipped with rotating filter wheels and specially manufactured filters. The camera imitates with a high degree of accuracy the colour sensitivity of the four different types of cones in bird retinas.
Among other things, birds see contrasts in dense forest foliage, whereas people only see a wall of green. For birds, the upper sides of leaves appear much lighter in ultraviolet. From below, the leaves are very dark. In this way the three-dimensional structure of dense foliage is obvious to birds. This in turn makes it easy for them to move, find food and navigate.

C. Tedore, Nature Communications, https://doi.org/10.1038/s41467-018-08142-5

Figure: Creative Commons Attribution 4.0 International License, http://creativecommons.org/licenses/by/4.0/