Drawing Selections with the Lasso Tools
The Lasso is another of the selection tools available in the toolbox. There are three variations:
- Lasso. Enables you to make a freehand selection around an object. This tool is useful for making selections when there's no other way to identify the item you want to select. It's also handy for cleaning up selections made by the Magic Wand, for example. Simply click the Lasso tool in the toolbox and drag around the area you want to select. Click your starting point to complete the shape. (Alternatively, when you release the mouse button, the marquee will be joined automatically to create a closed shape.)
- Magnetic Lasso. Useful when you have an object with well-defined edges because it finds the edges for you—all you need to do is move the pointer around the edge, and the selection is made automatically as you go. As you move, nodes (small filled boxes) appear on the selection marquee, as shown in Figure 3. If the Magnetic Lasso makes a mistake and the marquee isn't where you need it to be, press the Delete key repeatedly to back up until you reach the node that's in the wrong position. Press the Delete key to remove it, and return to the process of tracing around the edge of the object.
You can place a node in a position of your choice as you use the Magnetic Lasso. Click where the node should be and drag around the edge to continue your selection. This extra bit of control is helpful when navigating around areas where the distinction is unclear between the edge of the object and the background.
Figure 3 The Magnetic Lasso is a good choice for selecting around an object that has distinct edges.
- Polygonal Lasso. Lets you draw straight-edged selections around objects, which is handy for selecting items such as buildings (see Figure 4), where the edges are quite straight but perhaps not exactly square. (To use the Rectangular Marquee, the item you're selecting must be exactly square.) To use the Polygonal Lasso, click the corners of the area to create a polygon-shaped marquee and then click the starting point to close the shape, or double-click and Photoshop will close it for you automatically.
Figure 4 Use the Polygonal Lasso to make straight-edge selections around regular objects such as buildings or boxes.
You can switch between the Lasso tools as you work. For example, if you're using the Magnetic Lasso to make a straight-line segment, hold down the Alt key (Option key on the Mac), click once to start the straight-line segment, and click again at the end of the straight-line segment (see Figure 5). Then release the Alt key or Option key, click once, and continue with your Magnetic Lasso selection.
Figure 5 Using the Alt key (Option key on the Mac), you can switch to making straight-line and freehand selections while using the Magnetic Lasso.
You can also make a freehand selection while you're using the Magnetic Lasso. Hold down the Alt key (Option key on the Mac) and drag around the area you want to select. When you release the Alt key or Option key, the tool will return to working as a Magnetic Lasso. Similarly, when using the regular Lasso, you can make straight-line segments by using the Alt key/Option key process.
This switching behavior in the Lasso tools can take a little practice, but it's worth persevering because you get three powerful tools in one.