“Green Lantern” wasn’t the shining B.O. beacon that Warner Bros. had expected, with an estimated domestic opening of $52.7 million — less than either “Thor” or “X-Men: First Class.” But the comicbook pic’s light is far from snuffed, with a list of variables including overseas B.O. and ancillaries that make “Green Lantern” an important case study for Warners and DC Entertainment.

The Warner pic fell short of pre-weekend expectations of $55 million-$60 million, perhaps pointing to a growing fatigue with comicbook adaptations among U.S. audiences.

“Green Lantern” earned $17 million overseas, fueled by a good Russia haul; WB decided against a day-and-date international release to avoid competing with “Pirates of the Caribbean: On Stranger Tides.”

“Green Lantern,” which debuted at 3,816 Stateside locations, including 2,711 3D runs, marks the summer’s third comicbook tentpole after “Thor” and “X-Men: First Class.” Warner pic entered the weekend with aud interest comparable to both predecessors but scored less than either: “First Class” opened at $55.1 million; “Thor,” $65.7 million.

But “Green Lantern” didn’t have Imax screens like “Thor,” just 3D. On the other hand, “X-Men: First Class” had neither 3D nor Imax.

Just 45% of the “Green Lantern” opening gross came from 3D. (That falls in line with “Kung Fu Panda 2,” with 45%, and “On Stranger Tides,” which scored 46% of its opening from 3D, including 9% from Imax.)

Warner distribution exec Dan Fellman said that 3D has eased into a new groove. “When we started with 3D, the number of people going to see movies in 3D was larger, but that was because there was a curiosity factor,” Fellman said. “I think you’re settling into a number that’s still a healthy number.”

Meanwhile, the weekend’s other wide release, “Mr. Popper’s Penguins,” drew an estimated $18.2 million through Sunday. Most B.O. observers considered 20th Century Fox’s pre-weekend projection of $10 million to be modest, instead expecting $18 million-$20 million.

Paramount scored a solid soph-sesh perf for “Super 8,” which dropped 40% for an estimated weekend take of $21.3 million. Pic has been playing best with over-25 auds but likely broadened to younger moviegoers, especially since “Green Lantern” also played mostly (68%) to auds over 25. “Super 8’s” domestic cume is an estimated $72.8 million.

Brighter days for ‘Lantern’?

“Green Lantern,” budgeted at a reported $200 million — not cheap, but in line with similar vfx-driven 3D tentpoles — is the first DC Comics (redubbed DC Entertainment) pic to bow under Warners’ new streamlined corporate structure that joins all TV and ancillary divisions under one banner to help consolidate downstream revenues.

What does that mean for “Green Lantern” now? It’s hard to say, but it certainly takes some of the pressure off the pic’s opening perf. Centering on a second-tier character that dates back to 1940, “Green Lantern” struggled to entice auds under-25, which didn’t help beyond opening night, when the majority of that demo likely bought tickets. Pic dropped a sizable 22% from Friday to Saturday. (Both “Thor” and “First Class” fell just 8% after opening day.)

Warners’ Fellman said today’s grosses will be telling for the pic since nearly all kids are out of school during the week now. “If we left any money on the table it was with kids,” he said. “But we should be back to where we want to be during the week.”

“Green Lantern” scored a so-so B CinemaScore rating but did slightly better with under-18 moviegoers with a B+. That should help the film if it can expand its demo base over the coming week.

How much room the film has to grow domestically is hard to forecast, especially as Paramount readies to launch “Transformers: Dark of the Moon” on Tuesday, June 28, at 9 p.m. exclusively at 3D and Imax locations before expanding wide the following day. Warner’s final “Harry Potter” installment unspools on July 15, followed the next weekend by Par’s “Captain America: The First Avenger.”

The crowded domestic playing field puts pressure on “Green Lantern” to perform well overseas. Pic took an estimated $17 million this weekend from a handful of territories, including Russia and the U.K., where local auds shelled out a chart-topping $4.9 million. Russian wickets contributed $3.2 million, which ranked second behind “Super 8,” with $4.1 million.

Fox decided not to release international figures for “Penguins” this weekend since the studio released the film in just five small markets and won’t have actual figures until today. Domestically, the Jim Carrey family pic played well with auds, scoring an A- CinemaScore rating and playing best with auds under 25 at 58%.

Among the weekend’s top holdovers, Universal’s “Bridesmaids” continues to display shapely legs, down just 26% in its sixth frame; domestic cume is $136.8 million.

Fox’s “First Class” also held nicely, off 52% despite the entry of the similarly targeted “Green Lantern.” “First Class” has a domestic cume of nearly $120 million and an international tally at $163.2 million.

“Bridesmaids” got off to a good start in Australia — its first territory outside the U.S. — with an estimated weekend take of $6.8 million.

Par-DreamWorks Animation’s “Panda 2” won the overseas crown, taking another $52.5 million this weekend; international cume is $280 million. “Panda 2” has held on handsomely overseas, much like Disney’s “On Stranger Tides,” which has an international haul of $731.4 million.

Shining specialty players

Sony Pictures Classics’ “Midnight in Paris” expanded this weekend to 1,038 locations, up from 944, with an estimated $5.2 million. Pic is the year’s top-grossing specialty release to date, with a domestic cume of $21.8 million.

Still seeing some green is Fox Searchlight’s “The Tree of Life,” which took in another $1.1 million from 114 theaters, totaling almost $4 million.

Searchlight saw a disappointing launch for Sundance teen comedy “The Art of Getting By,” which estimated just $700,000 from 610 locations. That makes for a per-screen average of $1,148, soft even for the wider-than-usual release.

A pair of Sundance documentaries fared better: “Page One: Inside the New York Times” and “Buck.” “Page One,” which Magnolia released at two New York locations, scored a solid per-screen average of $16,500; “Buck,” which Sundance Selects bowed in both Gotham and L.A., averaged slightly less, with $16,100 from a total of four locations.