It's possible to photograph sections at different times of the day. The falls sit in a deep slot, leaving parts in shadow or sunlight as the sun moves across the sky. Late in the day, as the sun moves west, it appears in a slot between the trees at the top of the falls leaving it too bright to shoot. However, the lower part is in shadow allowing slow shutter speeds. Some experts advise photographers to use the morning light. I found the water much too bright to get the results I prefer. Maybe a neutral density filter would control the brightness. I don't own one. These images are a scanned 35mm slide, center, and 6x7cm slides left and right. The image, right is a recent (October 2016) digital one.