Layer-Based Compositing | Photoshop CS Savvy

Imagine that you have two transparencies on a light table, one on top of the other. When you look at them through a magnifying loupe, you see the effect of combined colors on the two superimposed images. Opposite colors (for example, reds and greens) might cancel each other and produce areas of dark gray, and colors that are closer to each other on the color wheel (for example, reds and yellows) might produce richer, more saturated oranges.

Now imagine that you have duplicates of the same transparency on the light table, and you are able to sandwich in filters that produce a variety of color relations between the two superimposed images. In Photoshop, these are the blending modes, and you apply them to an image in the Layers palette. The blending modes, which are described in Appendix C and illustrated in the color section, can be used to enhance color on an image. When you superimpose one layer on another, you can apply a layer effect to alter the color relationships and then precisely control the result by adjusting the opacity of the layer.

To demonstrate this effect, follow these steps:

Open the file Rinocerose.psd from the ch24 folder on the Photoshop CS Savvy CD. Figure 24.1 shows before and after versions of the image. (See color versions, C53 and C54, in the color section.) The original image on the left is divided into two layers. It lacks rich colors and appears flat.

Figure 24.1: The original image (left) lacks rich colors and appears flat. Stacking layers with similar content and applying a blending mode and opacity and fill adjustments can greatly enhance an image s contrast and color (right).
Hide the Rose layer by clicking the visibility indicator next to it in the first column of the Layers palette. Target the Rose layer.
Choose the Magnetic Lasso and drag it around the rhinoceros. The Magnetic Lasso will most likely not make a perfect selection, so you ll need to add to and subtract from the selection with the Lasso tool or the Quick Mask .
Choose Layer ’ New ’ Layer Via Copy to copy the rhino to a new layer. Name the new layer Rhino .
Target the new layer and choose Linear Light from the Mode list. The layer looks more saturated but a little too contrasty.
Drag the Fill slider to 65% to diminish the contrast. Drag the Opacity slider to 88% to bring out a little more detail in the shadow areas.
You ll now enhance the rose. Click the Rose layer s visibility indicator again.
Drag the Rose layer to the New Layer icon to duplicate it. Name the layer Vivid Rose and drag it to the top of the layer stack.
Choose Vivid Light from the Mode list, and reduce the fill to 55% to enhance the detail.

The image now appears much richer. The colors in the targeted areas are more saturated and have better contrast. Experiment with creating additional layers and applying different blend modes at varying degrees of opacity to vary the effect.