PARIS — Karl Lagerfeld’s done it again. In a season when many others were succumbing to the Eighties fever that’s swept the French fashion capital, he acknowledged the decade. But most of the terrific fall collection he showed on Friday for Chanel consisted of fresh, elegant riffs on the house’s traditional tailoring, often featuring lean coats worn over dresses and skirts. Here, one of them, smartly shaped in pristine winter white. For more on the season, see pages 4 to 10.