Photo finishes are made using strip or slit scan cameras. They are an assemblage of slices of something as it passes a certain point, such as a finish line. The same y axis at different points in time rather than different points in an x,y plane at an instant. As such they produce sometimes beautiful or plain weird distortions, from the arched backs and smeared limbs of Olympic cyclists and runners to pictures of aircraft propellers which appear impossibly separated from the nosecone.