Photographer-turned-director David Hamilton's favorite subjects-incest and voyeurism-are again given a workout in Cousins in Love. The largely female cast (many of whom seem a bit underage) enter into the soft-core goings on with enthusiasm. Hamilton's artistic utilization of shadows and gauzy focus help to take the viewer's mind off the utter lack of plot. Actually, there was a story to follow; after all, Pascal Laine adapted the screenplay from his own novel. Cousins in Love is satisfactory for its target audience, though, to paraphrase Variety, it's not likely to bring in new business.