Having worked both in celluloid and digital medium, megastar Amitabh Bachchan on Wednesday advocated preserving films for posterity by digitising them.

"We have forgotten and lost the word 'film'. There is no film, no celluloid. That's a huge change. Film was a very expensive commodity in my time so if there were retakes it was a huge pressure for us as well as for the producers.

"Now with digital, there is the freedom to take long shots. It gives you the liberty to shoot for several minutes at a time," Bachchan told media here when asked on the changes in cinema.

He was here to promote the upcoming Hindi thriller film "Te3N".

Batting for preservation of film footage, Big B said digital medium is beneficial as it will "restore all our past work".

"I think they should be transferred to digital as soon as possible," he observed.

Further, shooting in digital format gives the freedom to work with natural light, he said.

"We are used to working with lights, in digital you don't have to be conscious," he added.