Infrared Effects


The infrared photography process uses special film that is sensitive to infrared light rays that exist outside the visual spectrum, in addition to visual light frequencies. Although the visual light spectrum records to the film in a standard way, the light in the infrared spectrum also records to the film, augmenting the final image design.

Although infrared films exist in both color and black-and-white formats, this exploration focuses on replicating a black-and-white infrared effect. The black-and-white infrared films create a dramatic graphic effect that works well, especially given the graphic nature of black-and-white photography as a whole. Specifically, the infrared process for black-and-white images makes greens (such as grass and leaves on a tree) look abnormally brighter, while making blue skies look much darker.

Infrared levels are stronger in the morning and evening, when the sun is lower in the sky. As a result, evening skies may appear almost black in the image, and in very high contrast against white tree leaves or grass. Thus, you might want to adjust and compensate for these variables as you're modifying the source image. Remember that the ultimate criterion is whether you're satisfied with the final result, not whether you're adhering to the characteristics of the infrared process.

Cuna Tree
Nikon D2H
1/320 sec, f/6.7
Focal length 120mm

About the Original Image

There are many ways to achieve an infrared effect, although they all share a common approach of selecting the green and sky areas of an image and modifying them for the way they appear in the infrared process. The approach described here is especially effective in that it keeps each color area separate, allowing you to tweak all variables in a non-linear fashion, fine-turning the relationships between the various tonal areas.

The photo I started with is a singular tree near the fortress of Cuna, just outside of Siena. The area was lush and green, with sloping hills covered with trees and foliage. The late afternoon sun was just beginning to stretch the shadows a bit while creating a warm diffuse glow over the landscape. The strong greens and visible blue sky make it a perfect source image for this effect.

Building the Effect

The first step is to define and isolate the local areas you want to change. These areas usually include the green grass and trees, as well as the blue of the sky. The Select Color Range command is perfect for isolating areas of color because it allows you to sample a color within the image, set the tolerance for the exact color range desired, and click OK to create the selection.

With the image open, choose Select, Color Range to launch the Color Range dialog box. Enable the Selection radio button (it's located below the image preview section) and move the mouse pointer into the image. Click in a representative area of the grass for the foreground shade of green. Adjust the Fuzziness slider as needed, making sure to select at least some of the tones in the shadow areas (see Figure ). Click OK to complete the color-based selection.

Select the greens in the grass.

With the selection active, Copy and Paste the green information to its own layer. Because I wanted to treat some of the green tones differently, I repeated this process for the green tones in the distant tree line and for the top of the main tree. After pasting each separate green selection, I clicked the new layer titles and renamed them Foreground Greens, Treeline, and Treetop. In addition, I made a color selection for the entire sky area, which I pasted into its own layer and named Blue Sky.

I Shift-clicked the green layers in the Layers palette to select them all and chose New Group From Layers in the Layers palette menu. I named the group Green Group in the dialog box that appeared and clicked OK to group the layers. I highlighted the Blue Sky layer and repeated the process to create a group to control the tones in the sky, which I named Sky Group (see Figure ).

Group the layers.

Converting to Grayscale

The next step was to convert the color image to black and white. Again, there are many ways to accomplish this, but for replicating an infrared effect, it's best to use a gradient map adjustment layer. This approach maps the colors in a gradient to the tonal and color ranges of an existing image.

With the foreground and background colors set to black and white, select Gradient Map from the Adjustment Layer pull-down menu in the Layers palette. In the dialog box that appears, click the gradient strip to launch the Gradient Editor and select the Foreground to Background preset (hover the mouse over the preset swatches to see their names). Click OK and drag the new adjustment layer to the top of the layer stack, if necessary, to convert the image to black and white (see Figure ).

Convert to black and white.

Adjust the Blues and Greens

To turn the green areas white (as they'd be in a real infrared photo), I selected Curves from the Adjustment Layer pull-down menu in the Layers palette. I positioned the adjustment layer below the Treetop layer and above the Treeline and Foreground Greens layers, and added two curve points: Input: 25, Output: 15 and Input: 124, Output: 245. This arrangement increased the brightness of the greens throughout the image, from front to back (see Figure ). The next step was to create a focal point with the greens at the top of the tree (which is why I created a separate layer for this area, and left it above the previous adjustment layer).

Brighten the foreground and treeline.

I added a second Curves adjustment layer above the Treetop layer, with a single curve point of Input: 35, Output: 138. To restrict this curve adjustment to just the Treetop layer, I created a clipping mask with the Treetop layer as the base. To do this, I held down the Option key (the Alt key in Windows) and clicked the line between the adjustment layer and the Treetop layer (the mouse pointer changes to a mask icon as you do this). This action adds the bright, hazy-white effect to the top of the tree, which is central to a good infrared image.

I followed the same process for the Blue Sky layer, adding a Curves adjustment layer to make the blues darker, creating a clipping mask to restrict it to just the Blue Sky layer. The curve for the Blue Sky layer in this image had a single point: Input: 206, Output: 31 (see Figure ).

Darken the sky and lighten the tree.

With separate groups for the greens and blues and a master gradient map controlling the grayscale, you can control most of the variables and make adjustments to get the tones to blend seamlessly. My final step was to add a Curves adjustment layer just above the Base Image layer to darken down the center of the image and expand the contrast in the middleground. I added a single point to the curve: Input: 111, Output: 35 (see Figure ).

Adjust the source tonality.




The Art of Photoshop for Digital Photographers
The Art of Photoshop for Digital Photographers
ISBN: 0672327139
EAN: 2147483647
Year: 2006
Pages: 141

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