Romanticism was an art movement that originated in the late 18th century. It relates to the glorification of emotion in art. It was a reaction to the age of enlightenment and modernity.
Romanticism in landscape photography deals more with emphasising this emotion in the sublime and drawing out and exaggerating natural elements.
Below is an example of romanticism in one of Thomas Doughty’s paintings from around 1830. It portrays the landscape in a way the human eye couldn’t see it. Thomas exaggerates the colours and the textures of the landscape.