Adobe Photoshop CS5 for Photographers : The Ultimate Workshop



Magic wand tool

The magic wand tool can be used to select pixels on the basis of their luminosity values within the individual color channels that make up the composite image. For example, if you have a picture of a landscape with a blue sky and click in the sky area with the magic wand tool, it should just select the sky. That’s what most people expect the magic wand tool to do; but in reality it does not always perform that reliable a job. I find the magic wand tool works OK on low resolution images but that is about the limit of its usefulness. However, you can use the smoothing options in the Select menu to tidy up a magic wand selection. If you are going to create complex selections this way then really you are often better off using the quick selection tool or choose the Select Color Range option, which can also be used to create selections based on color values. Color Range provides all the power of the magic wand tool, but offers much more control. I rarely ever use the magic wand when defining critical outlines, but I do find it quite useful when I want to make a rough selection area that's based on color. In short, don’t dismiss the wand completely but don’t place too much faith either in its capabilities for professional masking tool. There are better ways of going about doing this, and these are explained in Chapter 8 of the book. Figure 1 below shows the magic wand tool Options bar.

Figure 1 The magic wand tool Options bar.

1 The magic wand tool can be used to create a selection of pixels which are similar in color to the point where you clicked. In this example I clicked in the blue sky area to select all the blue pixels surrounding the point where I clicked. Because the Contiguous option was switched on, the selection was limited to selecting neighboring pixels only. In other words, it only selected the pixels that were connected to each other.

2 I then deselected the Contiguous option in the Options bar, the magic wand tool wasnow able to select blue pixels of similar tonal value that occured everywhere in the image. you will notice how the magic wand now selecteded blue sky areas in other parts of the image as well.

3 Once most of the desired blue pixels had been selected I used the Select Grow command to expand the magic wand selection. Note that the Grow command will be based on the Tolerance value currently set in the Options bar for the magic wand tool.

4 This shows a view of the image after applying the Select Grow command. Note how more of the sky has now been selected. I could keep growing the selection till all of the sky was selected