When Robyn Davidson made her 2,000-mile walk across Australia in 1977 from Alice Springs to the Indian Ocean, Rick Smolan was commissioned by National Geographic to catch up with her (and her camels and dog) five times during the trip to take photographs.

That was in an age without GPS,  satellites and mobile phones. There was no way for Davidson to call for help, no way for her to be found. And Smolan was shipping film back to Washington and having no idea whether his pictures had worked.

Smolan’s Ted Talk about the assignment, published earlier this month, is both frank and fond. He discloses that he and Davidson got off to a really bad start…