Shutter speed is the key to waterfall photography. With a slightly longer shutter speed than usual, moving water will appear silky smooth in a photograph. The longer shutter speed makes it necessary to use a tripod or to steady the camera in some other way. It is also recommended to use a timer or remote to avoid moving the camera at all when pressing the shutter release button.
A longer shutter speed exposes the camera’s sensor to more light which makes it necessary to reduce the size of the opening of the aperture for proper exposure. Both the shutter speed and f-stop can be controlled simultaneously with the camera’s manual setting. Consider using bracketing to determine the best combination of settings for a properly exposed photograph of the waterfall and for the water to appear as silky as desired.