Function

• The lasso tool, found as the third icon from the top on Photoshop's Tools menu and looking exactly like its name, offers one of Photoshop's most customizable ways to perform selections. A selection in Photoshop is the user's way of establishing an area to perform work on. A user may select something to cut it out of the image, duplicate it, change its color or lighten the shadows within that area. Using the lasso is akin to taking a pen and tracing around the outline of something on a piece of paper -- a quick and fast way to set yourself up for the next steps of image editing.
  
  

Benefits

• A main benefit of the lasso is its speed of use. You simply click the tool and the cursor transforms into a tracer. Click the starting point for the image outline, trace around it and end up where you started. Photoshop then places a ring of dotted, blinking lines around the selected area. Unlike some of Photoshop's more complicated tools, there's no anchoring, twisting or turning of points to define the selected area. Using the lasso doesn't commit you to anything, either; simply right-click anywhere in the blinking dots and select "Deselect." The outline goes away and you can re-lasso the intended area.
  
  

Types and Variations

• The lasso is the most commonly used of its category, but right-clicking the lasso icon reveals two additional lasso tools -- the polygonal lasso tool and the magnetic lasso tool. Because of the settings in each of these, they are best used for very specific kinds of selections. The polygonal lasso tool works to set boundaries for selection on a straight-lined shape. After clicking the tool and the canvas, you don't trace around edges, you draw lines, so working with non-straight-edged images isn't possible. The magnetic lasso tool is helpful because it "grabs" onto the edge of whatever you're selecting, making for a cleaner selection. But occasionally, the magnetic lasso grabs something you don't want to, which may cause you to have to start over entirely and can be frustrating.
  
  

Considerations

• For a quick and dirty selection, you can't beat the lasso tool. But when you are performing extremely intricate selections, where a matter of a single stray pixel can damage your work, the lasso is probably not your best option. Others, such as the pen tool, which is actually for selections and not drawing, work better. Even if you zoom into the image so you can see the pixels when you use the lasso tool, you're at the mercy of your own hand's steadiness as you operate the mouse to drag the cursor around the intended selection.