02/11/2013 09:26 EST | Updated 04/13/2013 05:12 EDT

Zac Posen adapts his formula for fall fashion to add intimacy with smaller show at Plaza Hotel

NEW YORK, N.Y. - Zac Posen presented his smallest fashion show in years at New York Fashion Week, taking a breath from a whirlwind few months that included joining "Project Runway" as a judge.

For a designer who thrives on flashbulbs, cameras and frenzy, the change might seem odd. But in a backstage interview, he said an intimate show at the Plaza Hotel on Sunday was the best way to sharpen the focus on fall looks in a new collection that was thoughtful and intellectual.

"My fantasies about glamour or about society, about travel, all took place here growing up in New York. When you drive by great historical backgrounds, this is where Halston did his first shows, where Oscar de la Renta used to show," Posen said.

He added, "I just wanted to give everybody a sort of joyful, calm moment during the hustle and bustle and rush of Fashion Week. And have a moment to get into craft construction and sort of chic, effortless dressing."

"Effortless" might be a stretch. Part of Posen's signature are red-carpet gowns, such as the strapless, draped bustier ballgown worn by Crystal Renn and the architectural peplum gown with cutouts and sharp shoulders worn by Coco Rocha, take some time and careful steps to make it down the catwalk.

Posen's separates caught the eye of Chassie Post, lifestyle editor of Posen does particularly well on the site, she said.

"We saw several of these architectural stretch satin tops throughout and as separates were among my favourite pieces," she said. These grand tops seem a natural evolution from Posen's signature architectural gowns and were very strong paired with draped chiffon and velvet skirts, skinny pants, and even long sculpted evening skirts.

This collection was guided by "the mathematical equation of femininity," Posen said. He studied the science of how planets move and said he tried to capture that, hence the sharp shoulders mixed with curvy peplums.

The right models are a key part of Posen's equation, too, and some of them only do his catwalk.

"I adore my models. It's my family. ... I'm on call for them all year-round, they're always welcome at my home for dinner, always at my studio. It's very real and natural that way," Posen said.


Nicole Evatt contributed to this report.