Graduated filters are the mainstay of the landscape photographer. They are used to reduce the dynamic range between highlights and shadows; predominately, they are used to add definition to a bright sky while allowing the photographer to expose correctly for the main elements of the image.
Grads, as they are known, come in a range of different exposure levels and colors and can be an extremely useful tool for the photographer. So, what if you do not possess or have forgotten your grad filters? Is there a way to replicate them? Well, yes there is, using Photoshop or other image editing software. While you can never truly represent a graduated filter with software, you can get close. In this tutorial, we will show how it can be done using Photoshop.
First, you need to make sure it is going to be possible on your image. It’s best to start from an image that has some definition in the sky or from which you can pull some of the highlights back to get that definition. The best images for this are RAW images, because they use the full dynamic range of the camera’s sensor.
So, with our image open in Photoshop, we are going to increase detail in the sky first. To do this, from the Photoshop menu select Image > Adjustments > Shadows/Highlights. By default, Photoshop will add some Shadow adjustment; but for now, slide this slider back to 0.
We are going to drag the Highlight slider to the right, carefully watching our sky as we do it. We are aiming to darken the sky subtly, adding definition to clouds, if there are any, without introducing any image noise to the sky. When you are happy, click OK.
The next stage is to add a new layer to the image. This is done from the menu using Layer > New > Layer. Give your newly added layer a suitable name and click OK. You will now see your new layer appear in the Layers Palette on the right-hand side of the Photoshop Window.
Now it’s time to add the graduated filter to the image. Fortunately, Photoshop already includes a powerful Graduated tool found on the toolbar at the left of the screen. If you do not see it, right-click on the Paint Bucket tool and select Gradient Tool. At the top left of the Photoshop interface, you will now see a Gradient Bar. To adjust our gradient, click on the bar, this will open the Gradient Editor. The gradient we are going to adjust is on the bottom right of the gradient library and is called Neutral Density.
As you can see, the default Neutral Density runs from opaque to transparent, however we can adjust the gradient to suit. For example, if we want to add definition to a golden morning sky, we can make the darker end of the gradient the same color but darker than our image’s sky.
To do this, click on the lower left marker in the gradient bar, then select the color box beneath. From the color box that opens, select the desired color and once you’re happy with the way the gradient looks, click OK.
Next, we are going to apply the gradient to our image. To do this, make sure the newly created Grad layer is selected in the Layers Palette. You will now see that your cursor has changed to a small crosshair. Starting at the top of the image, click and drag this crosshair down to about one-third of the way from the bottom of the image.
You may need to experiment with this a little to get the desired effect. As you will see, the effect is too harsh, so we need to blend this layer into the background layer for a better result. To do this, again with the new Grad layer selected in the Layers Palette, click on Blend Mode, this is to the upper-left of the Layers Palette with the default of Normal. From the drop down box, select, Overlay or Softlight. Overlay has the stronger effect of the two, but we can reduce the effect further by sliding the opacity slider toward the left until you are happy with the result.
Once you have finished, you can save the file. If you wish to preserve the layers, then the best option is to save as a Photoshop PSD file, if you wish to save as a JPG, then it is best to flatten the layer first. This can be done from the Photoshop menu, Layer > Flatten Image.
There you have it, a simple, quick, and effective way to simulate a graduated filter using Photoshop.