Composited crab and sand
In the previous lesson 
, you learned how to do a number of image transformations using Photoshop menus and panels. Today you’ll see what the some of the most commonly-used Photoshop tools can do, and how to modify their impact using the Control panel.
This lesson is based on Adobe Photoshop CS4 Extended, but you should be able to follow along with earlier versions.
In this lesson, you’ll begin to learn how to use these Photoshop tools:
- Magic Wand tool
- Lasso tool
- Magnetic Lasso tool
- Hand and Zoom tools
- Move tool
- Burn tool
We’ll be combining a photo of a crab with a photo of sand. The crab is from Fort Bragg, California, and the sand is in Santa Monica, California. Click on each image to view and download the full-size photographs.
Using the Magic Wand Tool
- Open the large versions of the crab and the sand in Photoshop.
- Make sure the crab image is visible. If it is not, click on the document tab that says source-crab-lg.jpg.
- Select the Magic Wand tool from the Tools panel. It may be hidden in the fly-out menu of the Quick Selection tool (remember to click-and-hold on a tool icon to access its fly-out menu.)
Magic Wand tool
- Verify the settings in the Control panel. Make sure that the New Selection button is active, that Tolerance is set to 30, and that the Contiguous check box is checked. Tolerance means how many colors will be selected that are similar to the color of the pixel you click on. Contiguous means that the selection will only include pixels that are neighboring—the selection will not jump over into non-contiguous areas.
Control panel for the Magic Wand tool
- The Magic Wand tool selects flat areas of similar color all at once. Because the crab’s background is solid white, and the crab is very colorful, it will be easiest to select the background in the image. Start by click once with the Magic Wand in the white background. Most of the white background should be selected. The selected areas will have animated dashes around them. This moving outline is commonly referred to as “marching ants.”
- This selection is pretty good but leaves out some bits of white background. It also cuts into the crabs claw on the right a bit. We need to add to our existing selection. To do this, hold down the Shift key while you click with the Magic Wand in the white area between the crab’s body and his legs on the left. When you press Shift, it adds to the selection you already have.
Add to the selection
- Now that we have the majority of the white background selected, we can invert the selection to that it wraps around our crab buddy instead. Go to Select > Inverse. Notice that there are no more marching ants around the edge of the image window—just around the crab himself.
Next: Using the Lasso Tool 
Using the Lasso Tool
- Now we need to deselect the bit that cuts into the crab’s claw tip on the right side. It will help to zoom into this detail a bit. Select the Zoom tool from the Tools panel:
- In the Control panel, make sure that the Zoom In button is active:
- Click twice on the tip of the crab’s claw on the right side of the picture. If the claw tip is partly hidden at the bottom edge of the image window, use Photoshop’s vertical scroll bar to move it all back into view.
Zoom in to the crab's claw
- We need to draw around the edge of the claw to add it back into the selection. This bit will take a steadier hand. We will need to use a selection tool that gives us more control: the Lasso tool. It is the third tool down in the Tool box (and may be hidden in a fly-out menu.)
- In the Control panel, click on the Add to selection button so that you don’t need to press and hold the Shift key during the next step. Also make sure that Feather is set to 0px so that we get a crisp edge.
Lasso tool settings
- Now you will need to draw a loop around the claw tip. While keeping your mouse button pressed, start inside the current selection, come out to the top of the edge you need to add, draw down alongside the claw edge until you get to the bottom of the area you need to add, then draw from there back to your starting point.
Draw with the Lasso tool
New selection added
- If you let go of the mouse too soon, the Lasso tool will complete the new selection from where you let go. This is okay; just draw a new area to add to the selection where you left off.
- If you add way too much outside of the claw’s edge, simply switch to the Subtract from selection button in the control panel, and draw to cut the extra area out.
Selection too big
- Select the Hand tool from the Tools panel:
- Click-and-drag with the Hand tool from the top-left to the bottom-right a few times (to navigate up and to the left), so that we see the crab’s left shoulder in the image window.
- With the Add to selection button activated in the Control panel, add this bit (shown below) back in, where the bright highlights on the crab’s shell met up with the white background.
Another piece to add to the selection
Using the Magnetic Lasso Tool
- Zoom all the way out so that the crab fits in the image window: double-click on the Hand tool icon inside the Tools panel.
- There’s one more area that needs to be subtracted from the selection: the opening within the right-hand claw.
Last bit to subtract from selection
- Zoom into this region.
- Select the Magnetic Lasso tool from the Lasso tool’s fly-out menu:
Magnetic Lasso tool
- In the Control panel, click on the Subtract from selection button.
- The Magnetic Lasso tool “sticks” to edges where there is high contrast. You simply draw close to the edge and the Magnetic Lasso should snap to the edge, marking its path with tiny square markers. Click once to start the selection, then release the mouse button; simply drag the mouse slowly around the desired selection area.
Drawing with the Magnetic Lasso tool
- The bottom corner of this claw opening does not have enough contrast for the tool to “see” it. Click at any place along the edge to “help” the tool add a square marker to your selection.
- If you end up with a square marker way off the path, simply press the Backspace key to back up. Each time you press the Backspace key, you will undo the markers working back toward the beginning of your selection.
- When you all the way around the claw opening, hover your mouse over the first square. Your Magnetic Wand cursor should show a little open circle next to it. This indicates that you are ready to complete the path. Click once with your left mouse button to do so.
By the way, it’s okay if these selections don’t look perfect. You’re just getting the hang of making selections. We’ll soften the edge a bit to hide some of our imperfections. Later on, you’ll learn how to use the Pen tool to make very precise selections.
- Finally, use the selection tool of your choice to add this white bit back into the crab selection. It’s another highlight (not background.)
Final bit to add to selection
Refining and Saving a Selection
- Up in the Control panel, click on the Refine Edge button (you should still have the Magnetic Lasso tool active for this to be visible):
- In the Refine Edge dialog box, click on the On Black icon to darken the unselected areas to black. This allows us to see if there is any nasty white haloing around our edges.
- Set the numerical values as you see below, and click OK.
Refine Edge settings
- Double-click the Hand tool again to zoom all the way back out.
- Let’s save this selection you worked so hard on, in case you’d like to recover it at some later date. Go to Select > Save Selection…
- This command saves your outlines as an alpha channel, something you’ll learn more about later. Name the selection crab in the dialog box and click OK. (Note: You can later recover your selection by going to Select > Load Selection….)
- Save your file as crab.psd.
Next: Moving a Selection into another Image 
Moving a Selection into another Image
- It’s time to return the crab to its native beach environment. Start by selecting the Move tool for the top of the Tools panel:
- Here’s how to move the crab into the sand image (which is still open, right?): click-and-drag from inside the crab selection up to the document tab for the sand image, and—don’t let go of the mouse button yet—wait a moment while the sand image becomes visible and then drag the crab image down into it. Then you can let go of the mouse button.
Crab on the sand
- Still using the Move tool, click-and-drag on the crab again to move him into a better position.
- Save this combined image as crab-on-sand.psd.
Move the crab
Adding Depth with a Shadow
- We need to add a bit of shadow in the sand under the crab. Click on the Background layer in the Layers panel.
- Select the Burn tool in the Tools panel. It can be found in the fly-out menu under the Dodge tool:
- The Burn tool darkens areas of an image wherever you paint. We want to paint in a shadow with a light touch using a large, soft brush. In the Control panel, set the brush to 100px Master Diameter and 0% hardness. Set the Range to Midtones and the Exposure to 50%.
Burn tool settings
- Click-and-drag under the crab to paint in a shadow.
Shadow burned in
- To reduce the brush size to get the shadow smaller at the leg tips, press the [ key one or more times.
- Paint over some areas a second time to deepen the shadows, especially where the crab comes closer to the ground. If you want to paint a lighter shadow, reduce the tool's Exposure in the Control panel.
Darker, refined shadow
- The darker sand shows us that there’s still a bit of a white fringe around the crab. Click on the crab layer in the Layers panel.
- Go to Layer > Matting > Defringe….
- Set the Width to 1px. This will clip 1 pixel off the crab image all the way around. Click OK.
- Save your file.
Completed crab on sand
- The Magic Wand tool selects flat areas of similar color all at once. You can increase the Tolerance setting to expand the range of colors selected, or decrease it to narrow the range of colors.
- You can add to an existing selection by holding down the Shift key while selecting. Alternately, you can click the Add to selection icon in the Control panel.
- You can subtract from an existing selection by clicking the Subtract from selection icon in the Control panel (or hold down the Alt key while selecting.)
- Sometimes it’s easier to select the background first, then invert the selection (Select > Inverse).
- The Lasso tool allows you to draw the outline of your selection.
- The Zoom tool lets you zoom in and out of an image.
- The Hand tool lets you navigate around within an image when you are zoomed in. Double-click on the Hand tool icon in the Tools panel to fit the image within the image window.
- The Magnetic Lasso tool “sticks” to edges where there is high contrast. You simply draw close to the edge and the Magnetic Lasso should snap to the edge, marking its path with tiny square markers.
- You can soften and/or clean up a selection by clicking on the Refine Edge button in the Control Panel and adjusting the numeric settings. To preview the effects of your refinement, try one of the five preview modes near the bottom of the Refine Edge dialog box.
- You can save selections as a alpha channel (Select > Save Selection…) to be retrieved later if needed (Select > Load Selection…).
- When you have two images open in Document Tab view, you can move a selection from one image into another using the following method:
- Keep your finger down on the mouse button throughout this maneuver.
- Click and drag from inside your selection up to the document tab for the other image.
- Wait a moment for the other image to come forward.
- Drag the cursor down into the second image window.
- Release the mouse button.
- The Burn tool darkens areas of an image wherever you paint. The burn tool is a sort of painting brush. You can control how strong the burning effect is using the Exposure setting, and what part of the image is effected (Highlights, Midtones or Shadows,) in the Control panel.
- You can clip the outer edges of an image using Layer > Matting > Defringe…
Still have questions? Want to give me feedback to improve this lesson? I’ve love to hear from you in the Comments section below.