Aigner was born on 14 September 1901 in Érsekújvár, Austria-Hungary (now called Nové Zámky in Slovakia).
[1] By 1926, Aigner was a reporter for Az Est, the Hungarian newspaper group, and soon became a photographer with them.
As the Paris correspondent of the London General Press at the Stresa Conference of 1935, Aigner photographed Benito Mussolini, who was about to sneeze as the picture was taken.
The photo made the cover of Newsweek in 1940, and established Aigner as a photojournalist.
He then spent time at Princeton University taking photographs of Albert Einstein.