ON1 HDR From A to Z! ON1 HDR 2021 is a full-featured photo editor designed to create rich, detailed high-dynamic-range (HDR) images from two to 13 bracketed photos. With HDR 2021, you can take multiple shots of a scene, at varying exposure levels—accurately capturing shadows, midtones and highlights in different frames across the series—and then blend them together to create a final image that has a much wider tonal range than a single shot could do.