Today was Labor Day in America, a day for relaxation, and perhaps a last chance to enjoy the outdoor leisure activities of summer. It seemed a perfect time for posting this very interesting 3-D photograph by Ian Straffin of the "Super Spiral," a spinning carnival ride. Ian left the shutter open for three seconds to achieve the motion blur. And yet the ride operator and the seated woman are in razor-sharp focus; neither one of them moved at all, not even to breathe, or scratch their noses! Relaxation indeed.

Ian's photostream on Flickr is full of very good 3-D pictures, too many even to count. Browse through them, when you have the time.