Gaspard-Félix Tournachon (French pronunciation: [ɡaspaʁ feliks tuʁnaʃɔ̃]; 5 April 1820 – 20 March 1910[1]), known by the pseudonym Nadar ([nadaʁ]) or Félix Nadar, was a French photographer, caricaturist, journalist, novelist, balloonist, and proponent of heavier-than-air flight.

Nadar began to study medicine but quit for economic reasons after his father's death.

His friends picked a nickname for him, perhaps by a playful habit of adding "dar" to the end of words, Tournadar, which later became Nadar.

Nadar photographed a wide range of personalities: politicians (Guizot, Proudhon), stage actors (Sarah Bernhardt, Paulus), writers (Hugo, Baudelaire, Sand, Nerval, Gautier, Dumas), painters (Corot, Delacroix, Millet), and musicians (Liszt, Rossini, Offenbach, Verdi, Berlioz).

[5] Portrait photography was going through a period of native industrialization, and Nadar refused to use the traditional sumptuous decors; he preferred natural daylight and despised what he considered to be unnecessary accessories.

In 1886, with his son Paul, he did what may be the first photo-report: an interview with the great scientist Michel Eugène Chevreul, who at the time was 100 years old.

After Nadar invented a gas-proof cotton cover and draped it over his balloon baskets, he was able to capture stable images.

[7]: 164 On his visit to Brussels with Le Géant, on 26 September 1864, Nadar erected mobile barriers to keep the crowd at a safe distance.

[7]: 260 [5][8] In April 1874, he lent his photo studio to a group of painters to present the first exhibition of the Impressionists.

[15] Nadar was recognized for breaking the conventions of photographic portrait, choosing to capture the subjects as active participants.