Ektachrome is a brand name owned by Kodak for a range of transparency, still, and motion picture films previously available in many formats, including 35 mm and sheet sizes to 11×14 inch size. Ektachrome has a distinctive look that became familiar to many readers of "National Geographic", which used it extensively for color photographs for decades in settings where Kodachrome was too slow. In terms of reciprocity characteristics Ektachrome is stable at shutter speeds between ten seconds and 1/10,000 of a second.