The Magnetic Lasso works great for selecting objects on plain, high-contrast backgrounds because it can easily find the edge of the object. To draw a straight line, temporarily switch to the Polygonal Lasso tool by Option-clicking Alt-clicking on a PC where you want the line to start, and then clicking where you want it to end. Press Caps Lock again to switch back to the standard cursor. Besides the usual suspects like selection mode, feather, and anti-alias all discussed on The Rectangular and Elliptical Marquee Tools and The Rectangular and Elliptical Marquee Tools , you also get:.
Width determines how close your cursor needs to be to an edge for the Magnetic Lasso to select it. From the factory, this field is set to 10 pixels, but you can enter a value between 1 and You can also press Shift-[ to set the width to 1 and Shift-] to set it to Contrast controls how much color difference there needs to be between neighboring pixels for the Magnetic Lasso to recognize it as an edge.
Frequency determines how many anchor points the tool lays down. You need more anchor points to select an area with lots of details than for a smooth area. Setting this field to 0 makes Photoshop add very few points, and makes it have a point party. The factory setting—57—usually works fine. Use tablet pressure to change pen width. If you have a pressure-sensitive digital drawing tablet, turning on this setting—whose icon looks like a pen tip with circles around it—lets you override the Width setting by pressing harder or softer on the tablet with your stylus.
The box on The Joy of Painter has more about digital drawing tablets. It works best on images with a strong, in-focus subject and a soft, blurry background, like the one in Figure With decent contrast, the selection you get with this command is pretty darn good!
Rare is the photo where Focus Area generates a perfect selection, but you can tweak the result easily enough using the settings shown here. The disadvantage is that you only get straight segments! You can improve your selections by using a shortcut key to jump between the two. The Magnetic Lasso tool is almost like a combination of the other two lasso tools, and works best when there is good contrast between the area you want to select and its surroundings. There's no need to continue holding down your Shift key the whole time you're adding to a selection.
Once you've started dragging your mouse, you can safely release the Shift key. You'll stay in Add to Selection mode until you release your mouse button. I'll continue scrolling along my selection outline looking for problems, and here I've come across the exact opposite problem from what I had a moment ago. This time, I selected too much of the image around the person's finger:. No worries though, since we can remove parts of a selection just as easily as we can add to them.
This will place you in Subtract from Selection mode, and you'll see a small minus sign - appear in the bottom right corner of the cursor icon. In my case, I'm going to drag along the edge of the finger. When you're done, drag back outside of the existing selection:. Drag back to the spot where you first clicked, then release your mouse button to finish.
The unwanted area around the person's finger has now been removed:. You can safely release the key once you've started dragging. You'll remain in Subtract from Selection mode until you release your mouse button. Once I've scrolled all around the selection outline fixing problems by adding or removing parts as needed, my final selection with the Lasso Tool is complete:.
You can also simply click anywhere inside of the document with the Lasso Tool. As we've seen, Photoshop's Lasso Tool is an incredibly easy tool to use, and while it may not qualify as a professional-level selection tool, the ability to go back and fix problems with the initial selection can really help to improve your results.
Up next, we'll look at the second of the three lasso tools, the Polygonal Lasso Tool! For more on making selections in Photoshop, see our complete How to make selections in Photoshop series.
Now take the Rectangular Marquee Tool and make a selection around the dots. Finally, in the Edit menu, near the bottom, is the Create Custom Brush option. It is important to have rough plan of how your picture is going to turn out…unless you are going to do a completely random abstract piece. A rough plan will show the basic composition of the picture, even though you may change it as the picture develops. As my image was going to be a front view of a face, it was also important to have a certain level of symmetry.
Open a new psd and create a new layer above the background layer. Hit Ctrl R to bring up the ruler. Click and drag from inside the side ruler through to the middle of your image to create a Guide Line it should snap there.
If you are creating an image that is going to be roughly symmetrical then obviously just draw on one side. See the image below left. Move the newly flipped outline layer to match up to the original to complete the face. The Guide Line should help the two layers snap together.
Merge the two outline layers, and drop the opacity a bit. The rough plan layer will be discarded before too long. Hit Ctrl H to hide the Guide Line, as this is no longer needed. Finally change the background colour to something more appropriate. I chose a fairly dark blue as I wanted this colour to influence the whole image.
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