PARIS — “The goal is to maintain the spirit of Saint Laurent, the essence, but distill it down.” That’s how Tom Ford approached his much-anticipated debut for Yves Saint Laurent. And the collection he showed at the Rodin Museum on Friday was very Saint Laurent, from its focus on the classic smoking, shown here in white, to the singular beauty look: an ode to the sleek style of Betty Catroux. For more on the collection, including the retail and press reaction to it, and on the season, see pages 6 to 10.