Creating a waterfall image that has both a smooth waterfall look and detail in the water can be a challenge. This is particularly true for waterfalls that have high volumes of water or fast flowing water. The problem is that those longer exposures can, sometimes, result in a loss of water detail. This is not a matter of the image being overexposed. Rather, it is a matter of large amounts of white water passing the same pixels. The detail changes from one instant to another, and the pixels average out the detail in the water.
Figure 1 shows an image with this type of problem. There is almost no detail in the water. At first, one might suspect that the image was given too much exposure and that the water detail was lost due to clipping. However, a glance at the histogram from the raw converter (see Figure 2) shows that that is not the case. There are no clipped whites at the right side of the histogram.
So, that leaves the photographer with a problem. The highlights were not clipped, but there still doesn't seem to be any detail in the water. Actually, there is detail in the water. It just takes some work to get it out.
Basically, all that is required to bring out some of the water detail is to pull out the detail with the use of a steep curve. However, it is not a matter of just launching Curves and yanking on the tool. Using that approach would, likely, mess up the rest of the image. This situation requires a bit more sophistication.
The first step is to duplicate the Background image. This layer can be renamed the Water Detail layer. With the Water Detail layer selected, Curves is launched (use Image/Adjustments/Curves rather than a Curves layer). A steep curve (see Figure 3) is then used to pull the detail out of the water in the Water Detail layer.
After the application of Curves, the Water Detail layer will look like Figure 4. There is now some detail in the water. However, there are two problems with this layer. First, along with the water detail, we got some undesirable color. Second. Most of the image is too dark. Both of these problems are easily solved.
The color in the layer is easily removed by changing the Blend mode to luminosity. This Blend mode will only pass on the tonal information in the layer. No color information will be included. To ensure that only the water detail from this layer is added to the final image, without adding any information from the dark areas of the layer, a black mask is added to the layer. As is, this mask will not allow any information from this layer to be added to the image. To add in the water detail, the Brush tool is selected from the Tools palette. The Brush Tool is used to paint on the mask with white in the area of the falling water (use a low Opacity on the brush and gently paint in the detail). This will produce a mask as shown in Figure 5.
You have a great image. You went to a lot of trouble to capture it properly. You put a lot of effort into the editing to produce a high quality image. All you need to do now is to sharpen and print the image. You now have the chance to mess it all up! It's easy; just take that beautiful image and apply sharpening to the falling water.
You went to all that trouble to blur the water. It makes no sense to turn around and sharpen it at the end of the process. The simplest way to sharpen the image without sharpening the waterfall is to use a mask on the sharpening layer (if you have no idea how to sharpen on a layer, you might want to read my series on Sharpening).
The waterfall shown above is a case in point. A mask was created to protect the water from the sharpening steps. The mask that was created is shown in Figure 9. The Layers palette is shown in Figure 10. The image was sharpened with a two step approach, and the mask can be seen on both sharpening layers.
Waterfalls can be quite beautiful, but capturing that beauty and transferring it to a print requires skill and effort. However, the final print should make it all worthwhile.