Megastar Amitabh Bachchan says he has to put four of himself into action to keep up with his "favourite" actor Ranbir Kapoor's talent on the sets of "Brahmastra".

Amitabh on Tuesday night took to Twitter to share a few pictures from the sets of "Brahmastra". One picture shows Ranbir sitting on two chairs while Amitabh is seen sitting on four. Big B's tweet suggests he needs for of himself to keep up with Ranbir's talent.

"T 3452 - .. work starts early .. like 6 am .. rehearsing, blocking and then shooting it .. with one of my favourites .. I need 4 of those chair emoji (chairs) to keep up with his enormous talent...!" Amitabh captioned the image.

The megastar took to his blog and wrote: "A day of early starts .. 5 am .. on set to block by 7 am .. shoot it by 9 am .. and just got back .... with the favourite Ranbir... more later .. its at 5 am again tomorrow .." he wrote.

"Brahmastra: Part One" is set to release in five Hindi, Tamil, Telugu, Kannada and Malayalam.

Produced by Dharma Productions and Fox Star Studios, the film also stars Alia Bhatt, Nagarjuna and Mouni Roy.