The title is a bit misleading as the images are those selected from one collection, that of The Royal Photographic Society. The choice therefore is a bit restricted but is still an interesting mix. I would be most interested to hear what you consider the 20 most important photographs of all time from whichever source you like.
The Hippopotamus at the Zoological Gardens’ by Juan Carlos Maria Isidro Count de Montizon de Borbon, 1852 ©National Media Museum, Bradford
‘Soldiers of the Sky’ by Nickolas Muray, 1940 ©Nickolas Muray Photo Archives
In 1853, Prince Albert noticed how quickly the world of photography was developing, so urged the Royal Photographic Society to start collecting images quick smart, to be sure they recorded its rapid rise. And so they did. The result? A collection of more than 250,000 images, 8,000 items of photographic equipment and 31,000 books and documents, including some of the greatest examples of photography yet.
Now, for the first time, photography fans can witness some of the best images from the entire body of work. Drawn by Light, an exhibition running from 2 December 2014 to 1 March 2015 at the Science Museum’s Media Space, showcases shots by such high-profile names as Ansel Adams, Madame Yevonde and Lewis Carroll, right up to Don McCullin, Terry O’Neill and Martin Parr. From still lives, nudes and portraits to photo-reportage and landscapes, it spans the gamut of styles.

‘Afghan Girl’ by Steve McCurry, 1984
Science Museum has selected these 20 images from Drawn by Light, exclusively for Condé Nast Traveller, for you to lose yourself in. www.sciencemuseum.org.uk/drawnbylight
‘Aspen’ by Ansel Adams, 1958 ©National Media Museum, Bradford
‘Audrey Hepburn’ by Angus McBean, 1950 ©National Media Museum, Bradford
‘Bewengungsstudie Movement Study’ by Rudolf Koppitz, 1926 ©National Media Museum, Bradford

‘Nude on Sand, Oceano, 1936” by Edward Weston ©Edward Weston
Moonrise, Hernandez, New Mexico’ by Ansel Adams, 1941 ©National Media Museum, Bradford