Digital capture technology is really awesome and has truly changed photography, improving it in a multitude of ways. But sometimes, digitally captured images have a certain exaggerated colorfulness, that just looks a little off, for those of us raised on the old fashioned film days! I have found that this has to do with the way color gets saturated as contrast increases. Even standard rendering presets increase contrast a bit through a global RGB composite curve, often indirectly. It seems that when contrast increases this way a global increase in saturation results that increases the chroma, or colorfulness, evenly throughout the image. This makes shadow values unrealistically colorful. Our natural perception of color decreases with reduced light, such that, as a shadow approaches black, color saturation is gradually reduced to zero. If you can correct for the tendency to increase color in the shadows as contrast is increased, you can achieve a more natural sense of contest and 3D shape in the image.
Lets take a look using the following example:
Looking at the deep shadow at her right arm, we can see a subtle region of exaggerated color in the deep shadow. Reading the RGB values confirms this—the reading of 31,1,1 is unrealistically colorful—we can see a sort of band of extra deep color right next to the black shadow. This is the bane of digital capture, in my humble opinion! Lets see what happens when we fix this.
Start by selecting solid gray color from the adjustment layer icon at the bottom of the Layers panel – this type of layer is not available from the Adjustments panel, so you have to get it here!
The idea is to use this gray color to desaturate the underlying layers selectively – right now the solid gray covers up the whole image!
Now we will use Blending Options to change how this gray interacts with the image – select Blending Options from the layer options flyaway menu at the upper right corner of the Layers panel.
The Blending Options dialog is where we can adjust the layer blending so that the gray is only covering the shadow parts of the image. To do this move the white slider to the left until most of the image is revealed with only the darkest parts covered by gray!
Now we have to soften the transition of the gray color so it blends smoothly. To do this, break apart the white slider into two haves by option/alt – dragging it apart and to the left! Don’t hit “OK” yet – there’s one more thing to do…
The gray color now blends smoothly into the shadows…
Of course, we aren’t going to use the image like this—we can change the layer blend mode from normal to color, right in the Blending Options dialog!
Compare this image with the first in the series–click on the image above to see it at full size. The de-saturated shadows look darker, giving the image better contrast in the shadows, eliminating the band of rich color next to the darkest shadow. I often reduce the opacity of the de-sat layer just a bit and sometimes work the layer mask selectively to bring back a little color where I might like it—I did that here, masking it off her right side to “highlight” the shapely curves of her torso.
This is what the Layers Panel looks like for this image:
I finished this image off by pinching her waist, and adding a rough stucco texture to the wall – giving it just a little more dimension. More on this technique in a blog post here.
It is surprising how powerful this simple technique is! The subtle de-saturating of shadows most often results in more dimension of shape in the shadows and makes the image look more natural and less “digital”