Clint Eastwood's J. Edgar is no longer stamped Top Secret.

The movie originally intended for a debut at the Carmel Film Festival last month had a couple of high-profile Los Angeles unveilings this week. This time, technical snafus did not get in the way.

The first, its official premiere, took place on Thursday night, where Eastwood's biography of the controversial FBI director was the opening-night attraction at the AFI Fest in Hollywood.

The following night, J. Edgar came to the Los Angeles County Museum of Art for a screening and post-film Q&A with Eastwood, screenwriter Dustin Lance Black and actors Leonardo DiCaprio and Armie Hammer.

J. Edgar is a classic biopic, big and old-fashioned and a little lumbering. It has weight and gravity, with a spirited central performance by DiCaprio all but certain to receive recognition from Oscar voters – but it's also a commercial gamble, a film unlikely to engage young moviegoers and one that certainly isn't a slam-dunk Best Picture nominee.

Also read: Oscar Buzz: Raves for 'Tintin,' Lights Out for 'J. Edgar'

At the LACMA screening on Friday, the film was greeted with raucous applause; the audience at the Bing Theater gave Eastwood a standing ovation when he walked onstage for a Q&A that was part of the New York Times' Times Talk series, which is coming to Los Angeles this awards season.

Discussing the film with the Times' Charles McGrath, Eastwood was typically matter-of-fact: I just have grown up with J. Edgar Hoover as the top cop … I thought it'd be very interesting.

On the casting of DiCaprio: Leo called up and said 'I'd like to play that guy,' and that sounded great. The studio certainly didn't object.

Eastwood and Black also said they found parallels between the anti-Bolshevik frenzy of 1919-1920, which in Hoover's case turned into a lifelong paranoia over communism, and the post-9/11 atmosphere in the United States.

I think there are Hoovers out there today, said Black (Milk). If it doesn't speak to today, there's no point in making it.

DiCaprio said he found the character to be a crock pot of eccentricities: Hoover lived with his mother until he was 40, worked to overcome a stuttering problem, was obsessed with cleanliness and never married or had a serious relationship, except for the one with aide Clyde Tolson (Hammer), which may or may not have been sexual.

Eastwood's film touches lightly on some of these traits and comes down hard on others; it spends lots of time exploring Hoover's lust for celebrity and his use of the media to paint himself as the ultimate G-Man, but mostly looks away from the issue of whether Hoover and Tolson were lovers.

The story goes beyond whether they culminated [their relationship] on a sexual level, said DiCaprio. It's not really our business what happened behind closed doors.

The problem with this reasoning, though, is that a good chunk of the movie does consist of showing us (or speculating about) what happened behind closed doors – between Hoover and his mother (Judi Dench), Hoover and his assistant (Naomi Watts) and many others. In the end, it feels squeamish to back off in front of this particular door.

At the reception afterwards, reaction to the film was decided mixed, with one person saying I knew nothing about the story, and I was fascinated, and the next calling it a missed opportunity undermined by an overly programmatic script, in which Hoover tells his life story – or runs through his greatest hits – to a succession of would-be ghost writers.

I tend toward the latter camp, though DiCaprio tackles the meaty role with gusto and Eastwood keeps things clean and classy. (No cringe-inducing moments like the pop-song interlude in Invictus.) And I admired a moment late in the film that punctured the reliability of the accounts we'd been hearing for the past two hours.

One subject that was the subject of extensive post-screening discussion was the old-age makeup that DiCaprio and Hammer wear for much of the movie. At times, particularly on Hammer, the heavy prosthetics were inevitably distracting – and DiCaprio said the process created challenges to the actors that went beyond sitting still for the five or six hours it took to apply.

It's incredibly claustrophobic, said DiCaprio in the Q&A. You had to animate yourself in that makeup, because it tends to stiffen you as an actor.

Hammer agreed that the process was laborious, and said he was less patient than DiCaprio – so at the post-screening reception, I reminded him that on last year's The Social Network, David Fincher used computer graphics to put Hammer's head on another actor's body so that he could play twins.

As he was sitting in the makeup chair for all those hours, I asked, was he thinking about how Fincher could have done the transformation with CGI?

Absolutely, said Hammer, laughing. Any other director would have done it with CGI. Clint is the only guy who could get away with doing it the old-fashioned way, and it was great to surrender myself to that process.

That's what I love about this movie: it could have been made in the '50s in black-and-white, and it probably would have looked almost exactly the same.