The opening image for this column, taken in Iceland, is an in-camera HDR image taken with a Canon EOS 5D Mark III. It was created by combining three RAW files into a single High Dynamic Range (HDR) JPEG.
In-camera HDR processing, available in several camera models, doesn't compare to processing images in HDRsoft Photomatix or Nik HDR Efex Pro, two programs developed specifically to give you total control of your HDR images. Both programs offer dozens of creative and corrective controls to give you the best-quality HDR image.
By the way, subject movement, such as fast-moving leaves, can be a problem for HDR. However, movement can work when photographing waterfalls because the water is in slightly different places in different frames, and that can enhance the feeling of movement in your image.
Here's the average exposure in my three-image HDR Iceland waterfall sequence: 0 EV, +2 EV and -2 EV. I had to shoot HDR due to the contrast range of the scene: bright sky, bright water and relatively dark foreground.
Onsite, another way to compress the brightness range of a scene is to use a graduated neutral-density (ND) filter, which is dark on the top and gradually becomes clear on the bottom. When shooting film, I used a graduated ND filter in situations like this, but now with digital, I simply shoot HDR.
Other options for darkening the sky include using the virtual graduated filters built into Adobe Photoshop Lightroom and Adobe Camera Raw, and in Nik Color Efex Pro.
In addition to using HDR as a quick fix, a simple crop gave my image more impact. In looking at the image, I didn't think the dull sky added anything to the scene, so I cropped it out. Never underestimate the impact tight cropping can have on an image.