TURIN, Italy — The long linen with the faded image of a bearded man is the object of centuries-old fascination and wonderment, and closely kept under wrap. Starting Saturday, and for six weeks, both the curious and those convinced the Turin Shroud is the burial cloth of Jesus Christ can have a brief look. By late Friday, 1.5 million people had reserved their three-to-five-minute chance to gaze at the cloth, which is kept in a bulletproof, climate-controlled case.