How many superhero movies is too many?

Comic book movie bubble?
Comic book movie bubble?

There's nothing little about comic book movies, unless it's "Ant-Man."

Much of the talk about the Friday release of Marvel Studios' new superhero franchise has revolved around the diminutive appeal of a minor comic book character and what The New York Times called "a superhero infestation" on the big screen.

"Ant-Man" is projected to open at around $60 million for the weekend, which could still be a disappointing return for the studio whose "The Avengers" opened at $207 million in 2012.

But there are signs we're in a superhero-movie bubble and the era of the caped crusader could be ebbing. Just four movies came out in 2014 based on comic books, down from a peak of 13 in 2011, according to data from OpusData, a branch of Nash Information Services that tracks the film industry.

"These movies are still incredibly successful," said Bruce Nash, founder of OpusData. "But I think the peak was really the first Avengers movie."

The longer the studios draw the characters' narratives out, the harder it is to persuade an audience to plunk down for theater seats. The third or fourth iteration of a film might appeal to a die-hard group, but finding newcomers to the audience can be tricky.

"Spider-Man," which was part of the boom in superhero movies in 2002, made a whopping 306 percent ROI at the domestic box office. Subsequent Spider-Man movies paled in comparison, with 2007's "Spider-Man 3" at only 54 percent.

But even to get to sequel territory, a character has to have the appeal to pull in millions. "Jonah Hex," one of DC's attempts at a comic-movie crossover, made just $10.5 million at the domestic box office on a budget over $47 million. Warner is rebooting the DC universe on the big screen with a series of interconnected films over the coming years.

"Ant-Man" may be in the same territory as "Hex."

"What is the crossover audience?" Nash asked. "If you have a big fan base for a character like Spider-Man, being able to translate that into a movie is fairly natural."

But Disney chief Bob Iger insists that he's not worried about a little costumed competition. Disney acquired Marvel in 2009 for $4 billion and has dominated comic book movies ever since.

"We like the Marvel slate that we have coming up," Iger told reporters at the Allen & Co. media conference in July in Sun Valley, Idaho, according to Variety. "We think they're unique in many ways and have no concerns [about competition] whatsoever."

As journalist Mark Harris wrote in Grantland last year, thinking of comic book TV and movies, "A bubble reaches its maximum pre-pop circumference when the manufacturers of a product double down even as trouble spots begin to appear."

Instead of movies, studios and their corporations are focusing on driving production to TV and online media platforms. Production is cheaper and marketing can be tailored to a niche audience that's more likely to be receptive to the characters.

As CNBC's Jane Wells reported from Comic-Con last week, the annual festival of nerdiness was virtually movie-free this year. Presenters instead focused on television offerings and virtual reality rather than the silver screen.