While it’s not a tool that will prompt photographers to leave their physical graduated ND filter at home, it’s pretty powerful regardless. Here’s how to expand your photo-editing prowess with the Lightroom graduated filter tool.
When to use Lightroom’s graduated filter tool
Lightroom’s graduated filter is a great tool for photographers — but like any digital effect, it’s not infallible. So when should you use it? First, if you can use a physical graduated neutral density filter, do it. Graduated NDs are the original inspiration for the Lightroom tool. NDs reduce the exposure, but only in part of the frame. That makes them an excellent tool to avoid overexposing the sky in bright scenes. The problem is that NDs only work with straight (or fairly straight horizons). If I had used a ND on the photo of the bride and groom (below), the filter would have also darkened my subjects, not just the sky.
HDR, or taking multiple exposures of the same photo and merging them together later, is one workaround. But, HDR doesn’t work with moving subjects. And when you just want to add a subtle enhancement to the sky, HDR can be overkill.
Lightroom’s graduated filter tool is great for when an uneven horizon makes it impossible to use a physical graduated filter, since you can choose what areas of the photo you want to apply the filter to. It’s also a nice tool for adding more subtle effects than the HDR technique (and it’s also often simpler to do).
The basics of Lightroom’s graduated filter tool
First, there is nothing the tool can do if you don’t get the shot right in the first place. Once you overexpose the sky, you can’t get those details back. If the sky in your photo is a white mass with no cloud detail, the graduated filter tool isn’t going to help much. You want to shoot so that you can still see the outline of the clouds. While you can add color and contrast later, you can’t (easily) recreate those clouds. If you can’t make out the detail in the sky when you preview your shot on the back of the camera, bring down the exposure just a bit, by about 1/3 of a stop. Too much, and you won’t be able to recover the detail in the shadows. If you can, shoot in RAW and add in some fill flash on the subject.
Take a look at my original photo on the left. The sky is just dark enough to see the outline of the clouds. The bride and groom look a tad too dark to me, but just slightly — I know that, shooting RAW, the subjects can easily be lightened. I was able to recover the details in the sky using the graduated filter tool and lighten the subjects and foreground using Lightroom’s exposure slider.
Once you have your photo inside of Lightroom, head into the develop module. The graduated filter tool is inside the toolbox at the top of the right-hand sidebar. Once you click on the tool, you’ll see a panel similar to the “Basic” options, with sliders for color temperature, exposure, and more. Hover over the photo and your mouse will also change into an addition (+) sign.
Clicking from the edge of the photo, drag the mouse over where you want to apply the effect. You can move your mouse in a straight line, or at an angle to cover a portion of the photo that isn’t perfectly horizontal.
Once you’ve drawn out the filter, let go of the mouse. You can continue to adjust the placement of the filter at any time — simply drag the top or bottom lines to move the filter down or up. To tilt the effect more, move your mouse to the circle in the middle of the effect and you’ll see a two arrows — click and drag the mouse to tilt the effect. To see just where the effect will be applied, check “show selected mask overlay” underneath the photo.
Once you have the graduated filter placed, move back to the right-hand panel and use the sliders to adjust the graduated filter. Many of these controls are the same as the options Lightroom includes inside the basic editing panel. To mimic a graduated neutral density filter, turn the exposure down. Adding the effect in post means you’re not just limited to exposure, as you can also use the white balance slider to make the sky a bit bluer or even use the dehaze tool to eliminate some fog.
With the filter in place, you can deselect the tool in the top panel (or simply scroll down) to edit the image as you would normally. Since you likely underexposed the photo to keep some of the details in the sky, you can now create a proper exposure for your subject. Since Lightroom is non-destructive, you can go back and adjust the graduated filter at any time by selecting the tool again, then clicking on the circle over the middle of the effect.
How to implement advanced effects using Lightroom’s graduated filter tool
Lightroom’s graduated filter tool is easy enough to tilt for a straight but non-horizontal horizon, but what about horizons that are far from straight? What about when your subject juts into the sky?
Once back inside the graduated filter tool, at the top you should see New, Edit, and Brush. Click on the brush, then below the sliders, click on erase. Use the sliders to change the brush size and the feather. If you want Lightroom to help you color inside the lines, check the auto-mask option. Move your mouse over the photo and erase any of the areas that you don’t want to apply the filter to — it helps if you check the mask overlay option below the photo again.
Graduated neutral density filters are one of the filters that haven’t been completely replaced digitally. While digital editing can’t bring back extreme overexposure, Lightroom’s graduated filter tool is an excellent way to easily apply exposure and even color adjustments to only a portion of the image. While the tool is most often used for creating dramatic skies, understanding how to use the Lightroom graduated filter tool gives you more control over your final image.
