Instant intimacy can be a problem for performers paired not by Cupid but casting.

For others who are couples in real life, the challenge might be acting as if they are strangers. That was the case with Drew Barrymore and Justin Long in "Going the Distance," a romantic comedy about a cross-country relationship.

"That was definitely a little more challenging for them, but they're both very talented actors so they can imagine that they don't know each other and make it feel real," director Nanette Burstein said in a recent phone interview.

On the flip side, did Ms. Burstein worry they would break up, which might make for an awkward shoot?

"Initially, but once we got on set they just had a very close, comfortable relationship and were very professional, and it just didn't feel like it was going to go down that road."

Whether the couple are on, off, on-again or off-again seems to depend on the day and the celebrity gossip source, but they are co-starring in "Going the Distance," opening Friday.

Ms. Barrymore plays a San Francisco grad student and New York newspaper intern named Erin, and Mr. Long is Garrett, an A&R (artist and repertoire) scout for a record label. So she's in a struggling business, and he's in a line of work where everyone steals music online.

When Ms. Burstein shot the romcom in summer 2009, she didn't envision either industry turning around and thus destroying the premise of the movie -- falling in love is easy, coming by jobs in the same city hard -- and she was right.

As the wife of journalist Scott Anderson and friend to lots of other writers, she says the newspaper business is only getting worse.

"Even the general economy, it was so bleak at the time. I couldn't see it changing that dramatically in a year. Of course you can be wrong but it just didn't seem likely. It obviously has improved but we're not in a great place."

Until now, Ms. Burstein has been known for documentaries such as the Oscar-nominated "On the Ropes" about three young boxers, "The Kid Stays in the Picture," based on movie mogul Robert Evans' memoir, and "American Teen," tracking a half-dozen high school seniors in Warsaw, Ind.

"Going the Distance," with a screenplay by first-timer Geoff LaTulippe, marked a leap for the director, who wasn't quite sure how it would play out.

If you're making an observational documentary, she says, "You're filming in real homes and people choose on their own what to wear and they choose what to say.

"And in a fiction film, everything that appears on the frame, every slightest detail is a decision that you make. It's a different kind of process that way, just having total control. I enjoy having the control, actually."

Nevertheless, she cast actors with good improvisational skills and encouraged them to ad-lib after shooting what was written.

Take, for instance, a much-televised scene (on talk shows and commercials) where the amorous leads are reunited after an absence and cannot make it to the bedroom, stopping in the handy dining room instead.

"That scene on the page ended with the brother-in-law saying, 'They came in so fast I didn't know where to go,' and then the scene goes on and becomes even more hilarious and that was all completely improvised," she said.

So was a line spoken by Mr. Long's roommate who eavesdrops on an intimate phone call through paper-thin walls. "When Drew is being carried out of the bar, that was completely ad-libbed, all those lines," which are in keeping with the movie's R rating, by the way.

To add to the authenticity of interludes in which the lovers Skype or engage in racy phone calls, the actors were either just off camera or in the soundstage sets that served as Erin's bedroom in San Francisco and Garrett's apartment in New York.

Ms. Burstein wasn't necessarily intent on making a movie about a comic coupling but says, "I was just looking for something that was good. I don't know that I would ever do a traditional romantic comedy that is more of a fairy-tale type of story -- never say never, you never know -- but what attracts me more are the Judd Apatow-type of comedies.

"It doesn't matter if they're R-rated or not but they just have a level of humor and honesty and just realism, that's more interesting to me. That the premise is not forced or gimmicky and it's actually a real situation and you kind of go from there. Certain comedic situations can get a little over the top to make them funnier but most of the film feels more grounded."

To help the audience feel as if they were witnessing Erin and Garrett fall in love, Ms. Burstein did some guerrilla shooting in places such as Coney Island and Chinatown with the two stars.

"We shot that using two small HD cameras and all natural light and a minimum of crew and just improvised the whole thing. ... It was kind of an experiment. We didn't know if it would work or not but it actually worked quite well."

Ms. Burstein had no trouble gaining permission from the owners of a Chelsea pub to film outside on the sidewalk and inside where it doubled for an Italian restaurant with a memorable house wine.

That's because she and her husband, along with novelist Sebastian Junger, own the Half King Bar & Restaurant on West 23rd Street. Documentarian and barkeep?

"It's been running for 10 years," she said of the business that's been praised by outlets ranging from Wine Enthusiast to London's Guardian newspaper, which called it one of the top 10 bars in New York.

"It has a very loyal clientele. We have a great manager and chef that really run the day-to-day of it. It was hard the first few years in getting established; now it's pretty easy to run."

As for whether Ms. Burstein had any first-person experience with long-distance relationships, she did but that was before she met and married her husband.

The film business, which can take cast and crew members away for long stretches, can breed such arrangements and she adds, "I don't think it's at all uncommon these days. We travel around a lot, we're a moving society, we can't necessarily control where and when we fall in love."

Looking for more from the Post-Gazette? Join PG+, our members-only web site. You'll get exclusive sports content, opinion, financial information, discounts from retailers and restaurants, and more. Our introduction to PG+ gives you all the details.