Back in 2013, as Vancouver production was falling, a group called Save B.C. Film started lobbying for better tax credits to lure work. But even though it was an election year, incentives were not sweetened.

What a difference two years make. Today, Vancouver hosts 29 productions — including major Hollywood movies such as “Deadpool,” “Star Trek 3” and Steven Spielberg’s “BFG.”

What changed? Not the incentive scheme. Instead, credit the declining Canadian dollar, giving U.S. productions what amounts to a 22% boost.

“That has been the single most significant factor in the amount of work here,” says Brian Whittred, president of IATSE 669. “It’s just economics. People will produce where it’s cheaper to produce.”

Most notably, Vancouver is seeing an increase in tentpole pictures. “Feature films are more focused on shorter (spending periods) than TV series,” says Creative BC president Richard Brownsey, “so they might be more sensitive to the value of the dollar.”

For Julius R. Nasso, who’s producing the modestly budgeted ($10 million) martial arts pic “Darc,” the exchange rate was happenstance. “It was a surprise and a blessing,” he says. “We got 25% we weren’t expecting.” But he adds that given the tax incentives, the quality of crews and post services, he’d come back even if the dollar were on par.

With so many productions in town, crews find themselves leaping from job to job. “There’s a make-hay-while-the-sun-shines mindset because of the ups and downs of the industry,” Whittred says. “People remember those times a couple of years ago when it was quiet.”

Some professions face greater manpower shortages than others. For example, during pilot season in March and April, all available second-camera assistants and digital-imaging technicians in Western Canada were working. The union is striving to build up their numbers.

Because of the high demand, many in the trainee program were upgraded. “When it’s busy, that’s when people get their breaks,” Whittred says.

There are five or six good feature film crews in Vancouver, explains “Star Trek 3” production manager Stewart Bethune, who crewed up in advance, and managed to retain much of the personnel from “Tomorrowland” and “Mission: Impossible — Ghost Protocol” for his current pic.

“I’ve been able to work with the same group of people for quite a long time,” he says. “We have this sort of family that goes from show to show. They’re fantastic, and obviously studios think so too, because they keep hiring us.”

Bethune suggests the shortage issues have less to do with crews and more with stage space. “There’s a limited number of stages here because historically, as in most film-production cities, there’s inconsistent work, and real estate is expensive.”

But while crew and facility availability are crucial, productions still search for the best incentives coupled with a reasonable exchange rate first, Bethune admits.

Brownsey maintains that growth itself will increase capacity. “The industry is not fixed at a certain level,” he says. “If the demand is there, the industry will find a way to accommodate it, and adjust in whatever ways we need. The studios and labor unions seem to be adjusting.”

While the math may be tricky, he notes the city is not turning away business. Between being too busy or not being busy enough, Brownsey says, “too busy is the better problem.”