Film credits keep rolling and rolling . . .

Movie credits are now a standard feature of the typical Hollywood blockbuster.

Audiences watch scenes that have become more complex and dazzling than ever in their visual effects and technical mastery, then sit through end credits that seem almost novelistic in length: hundreds, or even thousands, of names in a blur of acknowledgment of the village it took to stage a superhero battle or bring robots to photorealistic life.

The names can occupy five to 10 minutes or more of a movie’s running time, and viewers often stay put to avoid missing a possible extra scene or a tease to other films in a franchise.

In the meantime, we learn about film jobs we had no idea existed. (Hello, render wrangler!)

And yet many names are still missing, and some in the industry don’t think the credits are long enough.

How did we get here?

It used to be much simpler. The earliest films, shown at nickelodeons at the start of the 1900s, had no credits at all, just the title.

“But then people started to recognize stars they liked,” said Dave Kehr, a curator for the department of film at the Museum of Modern Art in New York.

As an example, he mentioned the emergence of the silent-era actress Florence Lawrence, who was not credited in her earliest films but built a fan following to the point that her name eventually appeared on a movie poster, making her one of the first movie stars.

Credits grew in the following two decades, but not by much. They would all appear at the beginning of films, usually, in three or four title cards acknowledging the cast and principal technical players.

“In the ‘60s, the unions get a little more power, and they are able to get more of their names on the screen,” Kehr said.

Audiences began to see longer credits covering the full crew. One of the first lengthy sequences of this period was the Saul Bassdesigned closing credits for “West Side Story” (1961), in which many names were scrawled in graffiti on walls and street signs.

As productions grew more lavish and more complicated, more crew members were needed. But in the age of celluloid, studios had to be mindful of how long their credits would be. Film was more expensive to work with and process, so each added reel had an effect on the budget.

Now that films are primarily projected in digital, this cost is no longer an issue, and credits have ballooned to their greatest lengths in the past decade.

At least 50 films in the movie database IMDB. com have cast and crew credits that surpass 2,000 names each.

The credits for “Iron Man 3” (2013) include more than 3,700 names, along with 24 specialeffects companies. You’ll see “uncredited” next to many names on IMDB, meaning that their names did not appear on screen, but the credit sequence is still seven minutes long.

Yet visual-effects and computer-graphics artist Aaron Estrada, who is now overseeing a visual-effects startup called MetaPipe, said that regardless of the lengths of these credits, too many names are left out.

“I have several films that I’m uncredited on, even though I was working for the primary vendor of the visual effects,” he said.

The opening credits and how they appear are dictated by unions and contracts. The actor credits are negotiated in individual contracts.

“The key words you use in a contract are usually ‘size,’ ‘style’ and ‘duration,”’ said Ann B. Clark, a lawyer for independent producers and production companies.

The closing credits, however, are determined by the producers.

“All of the credits for a visual-effects company are generally provided by the company, and then there sometimes will be a negotiation,” Clark said. “For instance, if the production company received 100 names from a visualeffects company, they may say, ‘No, you’ll have to whittle that down to 20.’”

So, if a credit is not contractually obligated, how do you get one?

“I think some of it depends on who’s vouching for you,” Clark said, “and some of it depends on how many degrees of separation you are from the individuals who are actually preparing the credits.”

For now, lengthy credits are here to stay. Superhero movies have sweetened the experience with post-credit scenes that make sitting through the names a little less tedious.

“Guardians of the Galaxy Vol. 2” has fun with its scroll, occasionally inserting the words “I Am Groot,” then switching to the name of a crew member. There are also five credit scenes laying the groundwork for other Guardians tales.