It won’t be long now before Oscar season picks up momentum and film critics across the country set about surveying the ambitions and aspirations behind the year’s most “serious” and “substantial” films. For many writers, the autumn rush is the light at the end of a long, dark tunnel — the promised sunrise after a stretch of silly and frivolous summer blockbusters concerned chiefly with opening-weekend receipts.

Yet while some critics shun the summer spectacles (so many of which are critic-proof to begin with), these films stand as the clearest examples of where cinema and commercialism overlap; they are essential case studies offering observers a window into the motives of the film industry and the mind-sets of filmgoers. Which blockbusters resonated with audiences (“The Dark Knight”), and why? Which seemingly safe bets flopped (“Speed Racer”)? Which dark horses excelled (“The Incredible Hulk”)?

More to the point, what does all this mean for the movie buff, the theater owner, and the studio executive? There were lessons to be learned this summer in terms of filmmaking, marketing, ticket sales, and film criticism. Here are the five lessons I’m taking away from the summer of 2008:

Serious Superheroes Sell Tickets

One doesn’t have to go back that far to recall the silliness of the early entries in the comic-book genre. Remember the cartoonish “Teenage Mutant Ninja Turtles?” Or the naïve idealism of the “Superman” sequels? Tim Burton steered the genre in a darker direction with his initial “Batman” (1989), but he clothed the film in a safe blanket of camp goofiness.

But what began in 2006 with “Spider-Man 2,” which elevated comic book movies by playing up the emotions and realism of their stories, reached an apex this summer with “Iron Man” and “The Dark Knight” — two movies that gave us reluctant heroes overwrought with emotional scars and plunged into the national discussion about terrorism and the use of force.

The near across-the-board failure of war-themed movies may have given the makers of these films pause, but it didn’t last long. Their movies connected with audiences in a visceral, profitable way, taking in a combined $800 million at domestic box offices.

What once was about action and special effects is now about emotions and catharsis. Might Hollywood bigwigs see the profit potential in pumping money into smart and sophisticated scripts?

Wooing Women Pays Off

Forget about the all-important 15-year-old boys; we’re about to see Hollywood focus more of its marketing on the female filmgoer.

It’s difficult to remember, given the astonishing box-office success of the “Sex and the City” movie last May, that the film was never a sure thing. A week before its release, pundits were throwing around opening-weekend numbers like $20 million and $25 million. Anything beyond $28 million or $30 million would be an unexpected smash, they said. So when “Sex and the City” closed its first weekend with $57 million, shattering even the expectations of its own studio, it showed that a movie catering to an exclusively female crowd could strike gold.

More important, “Sex and the City” was not the summer’s only female-driven surprise hit. Three weeks prior, the romantic comedy “What Happens in Vegas” arrived on the same day as the heavily marketed science-fiction thrill ride “Speed Racer,” and was welcomed with devastating reviews. Yet it still drew $20 million (in only 3,200 theaters, at a healthy $6,200 average per theater) in its opening weekend. Again, most analysts took note, chalking the surprise up to women on the hunt for a summer romantic comedy. The one-two punch of “Vegas” and “Sex” showed Hollywood that blockbusters need not only be targeted to teenage boys (and their adult doppelgängers).

Bloggers Set the Tone

Much has been written about the decline of the film critic and the corresponding rise of the film Web logger, whose reviews splash onto the Internet before the establishment reviews have even gone to press.

For the summer’s biggest movies, it was the online film community that set the bar. More than a week before “Indiana Jones and the Kingdom of the Crystal Skull” screened for critics, an anonymous online review trashed the project, laying the groundwork for the public backlash to come. Much the same occurred with M. Night Shyamalan’s eco-horror spectacle “The Happening.” (Granted, the films went on to opening weekend totals of $100 million and $30 million, respectively.)

When it came to “The Dark Knight,” online writers fawned for months over the film and the performance of Heath Ledger as the Joker, demonstrating the power they possess to catapult a film into the stratosphere. Time will tell, but they may have also have laid the foundation for a legitimate campaign to award the late Ledger with an Oscar.

Franchises Can Fail

Yes, “Get Smart” was a safe bet, resurrecting a classic TV show for a Steve Carell-driven $38 million opening weekend. But franchises no longer guarantee a big opening weekend. People knew the name “Speed Racer,” but that title limped in with an $18 million debut. “The X-Files: I Want to Believe” was based on one of the most popular television shows ever, but only opened to the tune of $10 million. “Kit Kittredge: An American Girl” was based on a popular line of dolls and books, yet raked in only $3 million during its first weekend of partial wide release.

Franchises were once a sure thing. No more.

The IMAX Boost Is Big

By now, we’ve all accepted “The Dark Knight” as the year’s biggest hit. But its opening-weekend tally only surpassed that of “Spider-Man 3” thanks to the $6 million generated in the first few days by special Imax screenings.

Until this year, an Imax showing of a film meant only that the standard image was supersized on an Imax screen. But “The Dark Knight” actually employed Imax equipment in filming several key sequences, meaning that Imax audiences saw a different image than those in conventional, 35 mm environments.

Hearing this, audiences flocked to opening-night Imax screenings, leading theaters to organize additional 3 a.m. and 6 a.m. showings. With “The Dark Knight” making millions solely through Imax screenings at a length of 2 1/2 hours, it’s easy to see that standard, 90-minute blockbusters incorporating Imax extras could be the wave of the future.

This isn’t chump change, and Imax is no longer a minor, special-event affair. As studios aim to generate additional revenue streams, capitalize on midnight screenings, and maximize return viewership, they will inevitably give their films the Imax boost.

ssnyder@nysun.com