Amitabh Bachchan birthday: The Bollywood superstar as you've never seen him before

As Amitabh Bachchan turns 80 on Tuesday, fans of the Bollywood superstar are celebrating his life and work across the country, with some even gathering outside the actor's home in Mumbai, India's financial capital, at midnight.

Prime Minister Narendra Modi joined scores of other prominent figures in wishing the veteran actor on Twitter. PM Modi said Bachchan "is one of India's most remarkable film personalities who has enthralled and entertained audiences across generations".

A retrospective exhibition of his rare pictures and his early films is being shown in India to mark the occasion.

Beginning on Saturday, 8 October, a first-of-its kind festival of Bachchan's landmark early films, organised by the non-profit Film Heritage Foundation, is being held held over four days at 22 cinemas in 17 cities across India.

Led by Shivendra Singh Dungarpur, an award-winning filmmaker, archivist and restorer, the non-profit has been at the forefront of efforts to preserve 60 of Bachchan's films in a temperature-controlled archive in the city of Mumbai. The archive has "built an international reputation for excellence", according to director Christopher Nolan.

An exhibition of some 50 photographs, mainly sourced from the collection of SMM Ausaja, a film historian, author and memorabilia archivist, will accompany the screenings.

Mr Ausaja has been collecting film memorabilia for three decades and is the author of a number of books, including one looking at Bollywood through posters.

Here's a selection of rare images from the exhibition that show the actor at work.

This picture of Bachchan and wife Jaya Bhaduri was taken during the shooting of Abhimaan (Pride), a musical drama directed by famed director Hrishikesh Mukherjee.

In the film, Bachchan plays an insecure man who cannot cope with the success of his wife - played by Jaya - when she surpasses his popularity as a singer.

The film was released in 1973, only a month after Bachchan and Bhaduri got married and was successful at the box office.

Film critic Jai Arjun Singh calls it one of the "most popular Bachchan-Bhaduri screen pairings, with a beautiful soundtrack". Abhimaan was also one of the earliest hits of Bachchan's career.

Top Bollywood director Subhash Ghai picked Bachchan to star in a film called Devaa, which was eventually shelved for reasons which were never entirely clear.

Bachchan was apparently playing an outlaw in the film, which was abandoned after Ghai shot some scenes and also a dance number featuring the star, according to reports.

This picture is from one of the filming sessions in the mid-1980s.

Ghai and Bachchan never worked together after this aborted venture.

"I regret that I haven't been able to work with Amitabh Bachchan yet. I had gone to him with Devaa, it's my fault that the film didn't happen. I never got another opportunity," Ghai told an interviewer later.

"I've thought of making a film with him many times, but when it is 'the Amitabh Bachchan', you need a project that will justify his status and a role worthy of him," he said.

This photograph of Bachchan pinning down a villain, played by Ranjit, was taken on the sets of the 1973 film Bandhe Haath (Tied Hands). Behind the actors is the director, OP Goyal.

Bachchan reprised a double role as a thief in this thriller about crime and retribution. It was one of his early films which did not do well at the box office.

This picture of Bachchan and actress Raakhee is from the sets of a 1979 film called Jurmana (Penalty), directed by Hrishikesh Mukherjee. The two actors are seen with producer Debesh Ghosh in the background.

Bachchan played the role of a playboy in what turned out to be "an uneven film which was apparently a long time in the making", says writer Jai Arjun Singh.

Jurmana was one of the eight films Mukherjee and Bachchan worked together in.

The actor once said he didn't "feel like taking credit for his performances in Mukherjee's films, because he was simply performing what the director had expertly shown him", according to Singh.

This picture of Bachchan and the celebrated cinematographer Jal Mistry (left) was taken during an outdoor shooting of Mard, the 1985 action hit, directed by Manmohan Desai, who was responsible for making the star a mass-market hero.

In the film, Bachchan plays the son of a freedom fighter who grows up to fight imperial rule.

A critic at the time wrote that his "dominance in the film was undisputed... He was a superman without a competent foil, male or female".

Yet some were sceptical of the film's success. "It does reflect rather badly on the tastes of our audiences that a film like Mard could be a hit. But it is one of the top grossers of the year," wrote a critic in a film magazine.

This is a rare picture of Bachchan on the set of Hero Hiralal, a 1998 film directed by Ketan Mehta.

Also in the frame are Mehta (extreme left), actress Sanjana Kapoor (third from right), comedian Johnny Lever and producer Gul Anand (extreme right).

The star of the film was Naseeruddin Shah who played an auto-rickshaw driver who meets an upcoming actress, Roopa (Kapoor), and the two fall in love.

Bachchan made a guest appearance, external. This was the only time Mehta and Bachchan worked together.