A graduated ND filter is standard in the bag of any landscape photographer, right next to the polarizer. But unlike the polarizer (which can’t be reproduced in post-processing), the graduated ND is one of the many filters that does have a digital counterpart, although it may be less well-known than many.
The digital graduated ND filter is one of the tools in Adobe Camera RAW, which makes it accessible to both Lightroom and Photoshop/Bridge users. And although it may be a little harder to find it, using it is a matter of simplicity itself. The digital grad ND filter is a true drag-and-drop tool, applied as an adjustable layer to the RAW file.
The adjustments appear in the toolbar to the right, and cover a wide range of options. In general practice, I drop the exposure anywhere from .50 to 1.5 stops, while simultaneously boosting the Vibrance, Contrast, and Clarity a few points apiece. The exact amounts vary by photo, but since the tool is what-you-see-is-what-you-get, it’s easy to try out an adjustment, decide it isn’t right, and change it. And since the entire adjustment is a layer, it’s equally as easy to delete the whole thing without causing any harm to the image.
When you’re done using the digital grad ND filter, clicking another tool, such as the Hand, switches back to the regular adjustment panels. To return to the filter, just click it again and the currently applied filter layers appear with the start and end points. Clicking any of these points will select that adjustment layer and allow you to make changes.
Perhaps one of the best aspects of this tool is that it can be oriented in any direction. While its most common application is probably to darken skys in traditional top-down fashion, it can be applied to the image from any direction. For example, if your subject is centered, but you wanted to darken both the sky above them, AND the ground in front of them, you can apply two separate digital grad ND filters, each one fading out as it nears her.
The adjustment fields also make it possible to apply the filter in a less orthodox manner. For example, the exposure adjustment goes in both directions, making it possible to apply a graduated anti-ND filter to a section of the image, or to likewise manipulate any of the other adjustments in either direction. The filter’s main weakness, and especially when being used in this unusual manner, is that it begins and ends in a straight line. If you’re looking to make detailed, irregular adjustments, then you’ll want a different tool.
Personally, I love the digital grad ND filter and make much use of it. Although I do have a physical graduated ND filter, it’s often easier for me to “fix it in post” (despite all the negative connotations that go with that phrase). For example, I use the Cokin filter system, and prefer their slim filter holder, which only accepts a single filter at a time. With only one filter, I reach for the polarizer first, so if graduated ND is still needed, it has to come in post. And of course I’m human, which means that sometimes, I forget the filters (or holder) altogether, so having a digital alternative is not only easier, but sometimes a lifesaver as well.