Understanding Exposure Fourth Edition How Understanding Exposure, Fourth Edition: How to Shoot Great Photographs with Any Camera £15.31 In stock. Amphoto's #1 bestselling title of all time, now updated to reflect the quickly changing world of digital photography.. Start with a few sheets of tracing paper, sketching a copy of your yard's outline on each page. About two hours after sunrise, observe where light and shade fall and mark them on the tracing paper, noting the time. Repeat the process through the day, each time using a different sheet of paper. Stop recording about an hour before dusk. The average ISO sensitivity range is approximately 100 to 1600. Some digital cameras have an ISO range of 100 to over 100,000 ISO. ISO sets the amount of light needed for a good exposure. Just like with film, the lower the ISO number, the more light you need to get a properly exposed image. "/>Understanding exposure fourth