Filmmaker Pratim D. Gupta has a solid past as a filmmaker.

He began his career as a film critic and has been a very successful one at that, backing his reviews with solid research. But the film bug bit him hard and he became a filmmaker. His debut with a short film within a group of short films all done by journalists / film critics followed by his first feature film, a love story called Paanch Adhyay was no great shakes, commercially or in terms of the box office.

But one could glimpse his command over the language of cinema and this proved to be true with the films that followed. His second film comprised of three interlinked stories called Shaheb Bibi Gholam had a mature touch and did well. With Maacher Jhol however, he proved his command over cinema and its associated elements very well. Ahaare Mon came next which hardly made news.

But his new film Shantilal O Projapoti Rohossho (Shantilal and the Mystery of the Butterfly) redefines, in a manner of speaking, the genre of the thriller in Bengali cinema.

He spoke to Shoma A. Chatterjee interviewed him. Excerpts:

The title of the film is quite intriguing. How would you, as director, elaborate on it?

The title is in the same spirit of detective and adventure films. Like Indiana Jones and the Last Crusade or Harry Potter and the Order of the Phoenixor even Byomkesh O Agniban. The first part is the name of the protagonist and the second part is the particular chapter in his life. So we have this journalist named Shantilal trying to solve the Projapoti Rohoshyo.

This is your first thriller among the films. Why a thriller?

I love watching thrillers. Parinda is still one of my favourite Indian films. Then from international films, Se7en and Fargo are films I can keep watching a hundred times. Shaheb Bibi Golaam in my mind is very much a thriller. Shantilal O Projapoti Rohoshyo is a more moody investigative thriller which traces the journey of a deadbeat reporter.

You have said in your interviews about this film that you did not want to bank on established and much-used famous literary detectives like Byomkesh Bakshi, Feluda and the like. Why?

It is difficult to get the rights, firstly. And then there's so much comparison with other films. I'd rather create something new and original hopefully the character and the film will create their own legacy.

The very well-made trailer of the film shows that this film goes much beyond the thriller genre. Do you agree?

Yes, it addresses a lot of issues, especially the position of women in our society. Why make a film if you can't toss up a couple of things that really bother you personally? Also, how a newspaper journalist is nothing short of a truth seeker in his own right.

Do you evolve a different directorial strategy for each film since each one is different from the next?

I like to mix them up because I like watching films of all kinds. Of course, all of my films hinge on human relationships and I like it that way. But the writing and the style of making changes from genre to genre.

How much freedom do you allow your cast and crew to improvise on the script and why?

Not much actually because it's all there in the script. Because I have worked with Ritwick and Paoli for four films now, I know them and they know me. So there isn't much need to improvise. But I myself keep tweaking with every scene till the moment it's shot.

To me, "improvisation" includes the technical crew too specially the editor and the cinematographer. Do you agree?

The cinematographer has a lot of room for improvisation because when you are shooting hand-held and often reacting to what the actor is doing in a scene, subtle movements of the camera and shifts of focus of the lens can really make a difference.

How did you decide on the cast and crew? Ritwick is there in most of your films. What makes you cast him again and again?

I depend on him a lot in delivering what is there on my page. He can get under the skin of just about any character and I know he will never fail a film. We have become each other's habit and I see nothing wrong in us working with each other over and over again. I had worked with Ritwick in Shaheb Bibi Golaam and I felt that I had tapped just a fraction of the incredible talent that he is. So I wanted to do a whole film with him. So he was there in Maachher Jhol. Everyone has to be a good actor. Period. Even if he is the manager of the hotel and has two scenes. As for Ritwick, I had him in mind when I wrote the script. For the rest, I started casting after my script was locked.

Where was the film shot and how long did it take to complete from concept to censor certificate?

It was shot last year in Kolkata, Chennai and Singapore. It was scripted for the first time in 2012 and then there has been many, many drafts. The censor happened in July this year.

As director and as film critic for over 15 years, what is it that attracts you to the thriller genre?

That you are constantly engaged. If a thriller is made well, you'll not be able to switch off from the film and in a day and age when attention span has really come down, this is a very important factor.

Whose thriller films among international filmmakers do you hold close to your heart?

Christopher Nolan, the Coen brothers, David Fincher, to name a few.

In what way has your work as a film journalist helped or hindered your work as director?

It has helped my writing a lot and the exposure to film sets and film personalities has also helped in me becoming a better storyteller.

Which contemporary filmmakers in India do you admire and/or idolise?

Mani Ratnam, Zoya Akhtar, Thiagarajan Kumararaja.

Did the producer give you the freedom to work as you will?

Absolutely. He completely trusted in my vision and let me make the film the way I wanted it.

Anything more you would like to add?

I think it's high time that Bengalis take a little pride in watching Bengali films because we take so much pride in making them. There will always be big Bollywood films and Hollywood blockbusters but the youth needs to come in and watch Bangla chhobi. They won't (always) be disappointed.