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Section 2.4. Retaining an Existing Shadow in a New Background

2.4. Retaining an Existing Shadow in a New Background

Sometimes your client has an image in which he would like to have the object cropped out of the background but retain the shadow. If the object is on a light background, as in Figure 2-35, this is generally a simple matter of dropping out the background.

Figure 2-35. The background here has subtle coloring that the client wants removed

Figure 2-36. Drop out a white background with a curve or selective tool adjustment

Figure 2-37. Copy a four- color image and create a grayscale

I will usually make a selection of the object or the background (whichever is easier) and invert the selection (if necessary so only the background is selected. Then I use a curve adjustment or a selective color adjustment to drop out the background, as shown in Figure 2-36.

Figure 2-38. Using the same selection, copy the image to the four-color image's black channel

Note: If the object to be cropped is onsay, a tartan background, for exampleyou obviously cannot simply drop out the background. In a case like this, you would probably have to recreate the shadow from scratch.

If you have an image in which you want to retain the shadow, but have the shadow in black only, try this technique. First, make a path or selection of your background, and then make a copy of the image and change that copy to grayscale, as shown in Figure 2-37.

Figure 2-39. Delete the cyan, magenta , and yellow shadow channel information

Figure 2-40. Final result shows the chair and shadow successfully extracted from the background

Use the same selection of the background method used above, only this time use your new black and white image. Then copy and paste it into the black channel of the original four-color image (Figure 2-38).

Make sure you delete any color in the shadow in the cyan, magenta, and yellow of the image you are retouching, as shown in Figure 2-39.

The final results of your new black-only shadow are shown in Figure 2-40.

2.5. Grounding Objects with Shadows

With every action, there is an opposite and equal reaction. This applies to shadows as well. If you place a shadow underneath an object, some of this shadow should be reflected back onto the object, thus anchoring the object to Shadows the shadow and the surface on which it sits. Without this anchoring effect, objects will appear as if they are hovering (an effect you wouldn't want unless you were trying to make an object appear as though it were floating, as in Figure 2-41.

Figure 2-41. Before: original image without an anchoring shadow

Figure 2-42. After: reflection of shadow onto the oranges anchors them to the ground

To create this anchoring shadow, add subtle amount of shadow to the object itself on multiplied layer, particularly where the object gets closer to the ground or another object. As an object gets closer to the ground or another object, the shadow will become progressively darker . After the application of the anchoring shadow, the object appears properly grounded. Note the anchoring shadow around the underside of the oranges in Figure 2-42.

2.6. Common Shadow Mistakes

Figure 2-43. Incorrect: there is nothing in the image that explains the angle of the shadow

Figure 2-44. Correct: a shadow that stays on the horizontal, regardless of the object angle changes

There are a variety of common shadow mistakes; in this section, I'll go over a few and give you some tips on how to avoid them.

2.6.1. Incorrect Shadow Angle

Always make sure a shadow stays put on the ground in a horizontal fashion, regardless of how the image angle may change. Notice that in Figure 2-43 there is no mountain or wall to explain the position of the donut's shadow. In Figure 2-44, the donut is hovering at an angle, but the shadow correctly "sits" horizontally on the ground. The only time the angle of a shadow would change is if the shadow hit an object that is on an angle, like a wall or mountain.

Figure 2-45. Incorrect: negative-looking shadow not on a multiplied layer

Figure 2-46. Correct: shadow on a multiplied layer

2.6.2. Not Putting the Shadow on a Multiplied Layer

Creating your shadows on a normal, unmultiplied layer makes the shadow appear to have a "negative" effect because the color of the shadow "knocks out" color beneath it. The shadow ironically ends up having less density than the rest of the image, as in Figure 2-45.

Figure 2-46 shows how the same shadow should look when multiplied correctly.

Figure 2-47. Incorrect: a shadow added to a colored area with less color than the object being shadowed

Figure 2-48. Correct: the proper look of the shadow with full color in it

Occasionally when creating shadows on a colored area, it may not make sense to have the shadow on a multiplied layer because too much color will then be added to the background area. In this case, just make sure that the color you brush in for your shadow contains at least as much color information as the background behind the shadow itself, or else it will have a negative look to it as well.

You can see this effect in Figure 2-47. For example, if I have a red strawberry and the red portion of the image is 100 magenta , 85 yellow, 30 cyan, and 10 black, make sure the color information in your shadow has those values, plus whatever extra color you add to create the darker shadow color. The only things you will have to keep in mind are the ink density specifications, which will be covered in a later chapter.) For now, just make sure the color is there and the shadows look natural. Figure 2-48 shows our corrected example.

2.6.3. Incorrect Shadow Shapes

Poor shadow shapes are another common mistake. Make sure your shadow shapes properly relate to the shape of your object. If you are not sure what the shadow shape for an object may look like, if feasible , try and locate the object you are trying to create a shadow for in "real life," and have a good look at it. Or find a practical sized replica of the object that you can study. Place the object under a lamp and move it around to see how the shadow falls , or just take a walk outside and have a look at various shadow objects.

Figure 2-49. Incorrect: this shadow looks like a squished marshmallow with no gradation

Figure 2-50. Incorrect: this shadow looks like someone painted a gray bar under the car

Figure 2-51. Incorrect: these shadows look like pads under the object

Figure 2-52. Our car with a realistic shadow

The next few figures show the same object, a car, with different types of shadows. Note in Figure 2-49, that the shadows under the car look like they were printed with a squished marshmallow; there is no gradation at all.

Figure 2-50, the shadow looks like someone just placed a gray bar under the car.

In Figure 2-51, the shadows under the tires look like pads placed under the car.

Finally, Figure 2-52 looks like shadows do in real life.

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