{"id":295,"date":"2016-06-22T08:22:56","date_gmt":"2016-06-22T08:22:56","guid":{"rendered":"http:\/\/www.apogeephoto.com\/?p=295"},"modified":"2018-01-17T15:06:40","modified_gmt":"2018-01-17T15:06:40","slug":"earth-sky-contrasts-in-landscape-photos-working-with-photoshop-masks","status":"publish","type":"post","link":"https:\/\/www.apogeephoto.com\/earth-sky-contrasts-in-landscape-photos-working-with-photoshop-masks\/","title":{"rendered":"Earth & Sky Contrasts in Landscape Photos: Working with Photoshop Masks"},"content":{"rendered":"

Landscape photographers are bedeviled by the fact that the camera cannot record the full range of brightness that the human eye can perceive. But although this simple statement of fact describes a problem at a technical level, it ignores a far more important aspect of human perception–the ability of our minds to process images so that we \u201cperceive\u201d a wide range of contrasts in even the lowest-contrast real-world situations.<\/p>\n

The mind can adjust for contrast, color, and tone locally in the real world, but it cannot do so with the limited information available in a print.<\/p>\n

With the arrival of the digital darkroom, photographers can now undertake to manipulate images in ways that allow a viewer\u2019s mind to believe that the image it \u201csees\u201d is truly representative of what the photographer saw when taking the picture.<\/p>\n

In most outdoor photography, the histogram may assume something similar to a bell-shaped curve, such as seen here in this typical city scene with its histogram showing in the lower right corner.<\/p>\n

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\n\u00a9 2012 Gary Nored. All Rights Reserved.
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As you can see, most of the tones lie in the middle. The spikes are caused by buildings.<\/strong><\/p>\n

Here in the Chihuahuan Desert of Texas, the earth and the sky typically register with a great difference in brightness; moreover, giving each a contrast range that allows a photograph to be accurately seen requires different adjustments for each.<\/p>\n

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\n\u00a9 2012 Gary Nored. All Rights Reserved.<\/p>\n

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A<\/strong> typical Chihuahuan Desert scene displays a \u201ccamel-back\u201d shape as seen below. Notice the separation of the tones seen in the sky and those of the foreground. Even though the full range of tones is captured in the RAW file, no amount of simple brightness\/contrast manipulation can reveal the beauty of this scene.
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My way of working with this photographic challenge is to make use of my Photoshop tools. I apply two Curve Adjustment Layers<\/em>, one for the earth and one for the sky, each with a Mask<\/em> that is used to limit its action to one portion of the picture. I use this approach so often that I have written an action to create the layers, and it is the first thing I do when opening any photograph.<\/p>\n

Masks<\/strong><\/p>\n

A Mask<\/em> is simply a gray-scale image that, when applied to a Layer, conceals that Layer\u2019s content or editing-effect in the dark areas of the Mask<\/em> and reveals it in the light areas. Adjustment Layers<\/em> are always created with a Mask<\/em>, but you can add a Mask<\/em> to any layer.<\/p>\n

In the following image I\u2019ve taken the example image and added a Curves Adjustment Layer<\/em> with an extreme adjustment curve. Then I painted the right side of the Mask<\/em> black. You can see how the Mask<\/em> prevents the curve from affecting part of the underlying image.<\/p>\n

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\n\u00a9 2012 Gary Nored. All Rights Reserved.<\/p>\n

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Create the Masks<\/strong><\/p>\n

After opening the image and doing any minor clean-ups needed, add two Curves Adjustment Layers<\/em>.<\/p>\n

There are numerous ways of creating Masks<\/em> \u2013 you can fill them with gradients, derive them from the image itself, or simply free-hand them. Free-handing is the easiest, so let\u2019s start with that.<\/p>\n

1. After opening the image and doing any minor clean-ups needed, add two Curves Adjustment Layers<\/em>. Name one \u201cEarth\u201d and the other \u201cSky.\u201d<\/p>\n

2. Apply an extreme<\/em> curve to the \u201cEarth\u201d Layer<\/em>, similar to the one shown below. Modification of this curve will occur later. For now, its only purpose is to help draw the mask.<\/p>\n

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\n\u00a9 2012 Gary Nored. All Rights Reserved.<\/p>\n

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3. Activate the Layer Mask<\/em> icon by clicking on it. A white border appears around the icon.<\/p>\n

4. Using a large brush, very soft, loaded with black, start painting over the sky. Because the Mask <\/em>was selected, the paint applies to the Mask<\/em> rather than the original image. As you paint, the original sky begins to appear.<\/p>\n

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Both photos: \u00a9 2012 Gary Nored. All Rights Reserved.<\/p>\n

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Don\u2019t worry too much about changing part of the horizon. You can refine the mask later.<\/p>\n

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5. Paint the top of the image until the sky is completely restored to its original appearance. Once finished, the \u201cEarth\u201d Layer<\/em> should look something like this.<\/p>\n

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6. It is important that the \u201cEarth\u201d and \u201cSky\u201d Masks<\/em> fit together accurately. The quickest way to ensure the fit is to simply copy the Mask<\/em> you\u2019ve created for the \u201cEarth\u201d layer into the \u201cSky\u201d layer and invert it. I usually Alt-drag the \u201cEarth\u201d Mask<\/em> to the \u201cSky\u201d Mask<\/em> and agree to replace it when queried. Then I invert the \u201cSky\u201d Mask<\/em>. The Adjustment Layers<\/em> look something like this.<\/p>\n

There are now two Adjustment Layers<\/em> with complimentary Masks<\/em>, one for the earth and one for the sky and the curves can be adjusted to enhance the image. You can click one layer or another to see how the layers histogram reflects only what it can \u201csee\u201d through the Mask<\/em>.<\/p>\n

Editing the Photograph<\/strong><\/p>\n

Bringing out the tonal range and contrast of the foreground is often all you will need to do. I\u2019ve adjusted this image\u2019s \u201cEarth\u201d curve<\/em> to brighten the ground and applied an \u201cS\u201d curve<\/em> to bring out the contrast.<\/p>\n

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\n\u00a9 2012 Gary Nored. All Rights Reserved.<\/p>\n

In this image I decided to brighten the sky just a bit. Here\u2019s the sky curve for the finished editing.<\/p>\n

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\n\u00a9 2012 Gary Nored. All Rights Reserved.<\/p>\n

The image is completed to my satisfaction. As you can see, this simple technique is very powerful.<\/p>\n

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\u00a9 2012 Gary Nored. All Rights Reserved.<\/p>\n

Original Image<\/strong><\/p>\n

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\n\u00a9 2012 Gary Nored. All Rights Reserved.<\/p>\n

Finished Image<\/strong><\/p>\n

When a Simple Free-hand Mask Won\u2019t Work<\/strong><\/p>\n

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\u00a9 2012 Gary Nored. All Rights Reserved.<\/p>\n

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Sometimes you can\u2019t brush your way to perfection. In these cases, you may need to create your Adjustment Masks<\/em> from the image itself. The process is more complex, but the principles are the same. Consider this hoodoo<\/a> image (also called a tent rock, fairy chimney, and earth pyramid).<\/p>\n

As you can see, there\u2019s no useful horizon line in the image and hand-painting with a soft brush just won\u2019t work. But I wanted to enliven the hoodoo, so I decided to generate a Mask<\/em> from the image itself. I liked the sky just the way it is, so I needed a Mask<\/em> to protect it from unwanted changes.<\/p>\n

The place to start is with Photoshop\u2019s Channels Palette<\/em>.<\/strong><\/p>\n

1. Open the Channels Palette<\/em> and examine each of the channels, looking for the one with the best contrast. In this case (as in about 99% of the cases for landscape work) the best channel is Blue.<\/p>\n

2. By turning off the other channels and selecting the Blue Channel<\/em> you can see the blue information for the image.<\/p>\n

3. Use a copy of the Blue Channel<\/em> to make the Mask<\/em>. Duplicate the Blue Channel<\/em>. The new channel will be labeled \u201cBlue copy<\/em>.\u201d<\/p>\n

4. In reality, a Channel<\/em> is just another image \u2013 in grayscale. Use a Curves Adjustment<\/em> to intensify the difference between the sky and the foreground in the Blue copy Channel<\/em>.<\/p>\n

5. Simply moving the white and black points creates a Mask<\/em> that\u2019s just about ready to use. Use a black paintbrush to fill in the white areas in the foreground.<\/p>\n

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\nAdjusted curve for blue channel.<\/strong><\/p>\n

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F<\/strong>inished Channel
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To use this Channel as a Mask<\/em><\/strong>, select the entire image (in the Channel Palette<\/em>) and copy it.<\/p>\n