Naval scenes are very common, and battle scenes and "ship portraits" are mostly considered as a branch of marine art; the development of other large types of military equipment such as warplanes and tanks has led to new types of work portraying these, either in action or at rest. In 20th century wars official war artists were retained to depict the military in action; despite artists now being very close to the action the battle scene is mostly left to popular graphic media and the cinema. The term war art is sometimes used, mostly in relation to 20th century military art made during wartime.