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The Magnetic Lasso tool

From: Photoshop CS4 Power Shortcuts

Video: The Magnetic Lasso tool

Let's talk about some power shortcuts for the Magnetic Lasso tool. Now it's a little bit different than its cousins, the Regular Lasso tool and the Polygonal Lasso tool. The difference is that the Magnetic Lasso tool is an edge detection tool. It tries to put down a selection around edges. It defines edges as light next to dark, so dark pixels next to light pixels. Now the first thing you should know about the Magnetic Lasso tool is that it's actually using up a circle to look for edges within. Right now that cute little icon that gives you little magnet on the Lasso tool isn't really all that helpful.

The Magnetic Lasso tool

Let's talk about some power shortcuts for the Magnetic Lasso tool. Now it's a little bit different than its cousins, the Regular Lasso tool and the Polygonal Lasso tool. The difference is that the Magnetic Lasso tool is an edge detection tool. It tries to put down a selection around edges. It defines edges as light next to dark, so dark pixels next to light pixels. Now the first thing you should know about the Magnetic Lasso tool is that it's actually using up a circle to look for edges within. Right now that cute little icon that gives you little magnet on the Lasso tool isn't really all that helpful.

So I'm going to turn this cursor into a precise cursor by pressing the Caps Lock key. The Caps Lock key will convert that magnet into the circle. That is the size of the area that the Magnetic Lasso tool is looking for within it for edges. Of course, you can change the size of that just like any other brush by using your Right Bracket key or the Left Bracket key to make the brush larger or smaller. The way that the Magnetic Lasso tool works is you click once to set a start point and then move the mouse along the edge of the image. Every once in a while, the Magnetic Lasso tool will then drop down anchor points. And you don't have to worry about being too precise here. It looks for that contrast within a given area. Some users complain because sometimes the Magnetic Lasso tool doesn't seem to know where to drop a point down. So I'm going to zoom in, while I'm using the tool here. You can just do Command+Plus/Ctrl+Plus. Here, when we get to this edge here, Magnetic Lasso tool doesn't know which edge to jump to, because there are two valid edges within that brush size.

So whenever that happens, you just click on manual point. If you click, you drop down on anchor point by hand, and then you can just continue along your way. So typically that happens around sharp corners when you need to make a manual adjust there. At any time, if you need to pan the image, you can hold down the H key or the Spacebar to pan. Then you can just continue going around the edge. Here again, you can do it very quickly. It's pretty accurate. If for some reason, you want to change the amount of contrast that the Magnetic Lasso tool is using or looking for, you can use your Period and Comma keys, or the Greater Than or Less Than keys, to adjust the Contrast field. You can see up in the Options bar, it's changing 11, 12, 13 and so forth. That's just giving a clue to the Magnetic Lasso tool, how much contrast needs to be seen before it considered it an image.

All right, so we'll click on a manual point here, and we'll just continue going around the outside of this flower. I'm going to ahead and zoom down once by doing Command+Minus/Ctrl+Minus and we'll Spacebar around to pan the image. I'm going to go ahead and complete this. One little tip about the Magnetic Lasso tool is don't worry about getting that perfect. This tool is not about getting a perfect selection the first time. It's about doing 80% to 90% of the work for you. You're going to have to refine your selection, once you've made your base pass out the outline here. I'm going to show you where you'd want to do that. When you get back to the beginning, you just double-click to complete that selection. You can see it did a reasonably good job. There are some spots here that I'm going to need to adjust and what not. Rather than trying to refine that with this Magnetic Lasso tool, I'm going to teach you to go into the Quick Mask Mode and switch to a real selection tool and what do I mean by that.

I want to press Q to go to Quick Mask Mode, and then we'll come zoom in, Command+Spacebar or Command+Plus and you get it dialed in where we want it. I'm going to press my B key for the Brush tool, and this is where I want to turn off the Caps Lock key. Because right now, I don't see my brush circle, I see a precise target, because the Caps Lock key is still turned on. So I'm going to turn that off. Now I can see this as my brush. I'll make it a little bit smaller. Now, since I'm in the Quick Mask Mode, I can paint with black and white to add or subtract to the mask. If I paint with black, I'm adding to the mask. So I'm going to undo that. I'm going to switch my colors, X for Exchange to take away from the mask. I might take this opportunity to show you precise cursors or full size brush tip. Right now, it's just this default circle. I'm going to go on my Preferences, Command+K, Ctrl+K, and in my Cursors category, I'm going turn on the Full Brush Size Tip and Show the Crosshair in the Brush Tip. That's going to give me a much more accurate view of how big my brush really is.

Okay, I'm going to make my brush just a little bit harder by doing Shift+], taking it all the way to the edge of making it harder, and then come back one or two Shift+[. So here I'm subtracting from my mask. I'm going to type X to] exchange that, and I'll just go really, quickly around the edge of the flower. I'm just holding down the Spacebar to pan. I'm just going to touch up the edge here. You can see it's much faster to do this with the Brush tool, than it is to try to go back and make it perfect with one of the Lasso tools. Here I went too for in so, X for exchange, and we'll just paint in a little bit on there and just continue to pan around. Look, I want to get rid of that little black spot, so X for exchange. I'll just come in there a little bit, and we're just going to go around the edge, holding down Spacebar or the H key to -- I'm going to pan around a little bit. And it's really up to you.

So this is fascinating, watching me click around, but you guys get the idea. It doesn't take all that long to refine that mask just a little bit, and we'll finish this up. Right there, X for exchange again, and that's good enough for what we're trying to pull off here. Fit to Window, Command+0, Ctrl+0 and then, if I press the Q key again, I'm back where I have a descent selection. Then I can lift that flower up to its own layer. Command+J/Ctrl+J to duplicate it. Then we can turn the Background layer off, and you can see I've got a complete selection there. So main takeaway there is you control the size of the area that the Magnetic Lasso tool is looking for by using your Right Bracket and Left Bracket keys.

If you want to control little bit further and tell Magnetic Lasso where to drop a point down, just click. Then one thing I didn't mention, let's go back here real click, if I switch back to the Magnetic Lasso tools, turn on Caps Lock key again to get the precise cursor. Sometimes, you're dropping points down that you didn't mean to. If that happens to you, just hit the Delete key in your keyboard and it backs up to the last anchor point. If I keep deleting, eventually I get an anchor point that I still like. There is an errant one, if you can see that. So I'm going to hit Delete and get rid of that extra point. So that's just one last tip for using the Magnetic Lasso tool. Just hit your Delete key if there is an errant anchor point that you don't want to include in your selection.

Show transcript

This video is part of

Image for Photoshop CS4 Power Shortcuts
Photoshop CS4 Power Shortcuts

191 video lessons · 10734 viewers

Michael Ninness

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  1. 1m 43s
    1. Welcome
      1m 0s
    2. Using the exercise files
  2. 48m 33s
    1. The Make Better key
      2m 48s
    2. Tool shortcuts
      2m 50s
    3. Spring-loaded tool shortcuts
      1m 43s
    4. Zooming
      2m 35s
    5. Bird's-Eye View
      1m 50s
    6. Hiding panels
      2m 24s
    7. Changing brush size and hardness
      2m 59s
    8. Resetting and swapping colors
      2m 34s
    9. Opacity
      2m 30s
    10. Labels and arrow keys
      3m 15s
    11. Scrubby sliders
      3m 7s
    12. Measurement system overrides
      2m 14s
    13. Auto Select Layer
      2m 42s
    14. Nudging
    15. Previewing, resetting, canceling, and applying
      1m 39s
    16. Context menus
      2m 41s
    17. Undo
      1m 59s
    18. Editing keyboard shortcuts
      3m 43s
    19. Discovering what's new and finding help
      3m 1s
    20. Resetting preferences at launch
      1m 7s
  3. 46m 37s
    1. The Application frame
      2m 16s
    2. The Application bar
      1m 45s
    3. Opening files from Bridge
      1m 51s
    4. Working with tabbed documents
      2m 7s
    5. Cycling through open documents
    6. The Arrange Documents widget
      1m 22s
    7. Moving layers between documents
      1m 47s
    8. Keyboard shortcuts for tile options
      2m 7s
    9. Stop tabbing my documents!
      1m 50s
    10. Panning and zooming all windows
      2m 40s
    11. Closing all documents
    12. Open GL navigation
      2m 27s
    13. New document tricks
      1m 22s
    14. The Rotate view
      1m 37s
    15. Cycling through the screen modes
      1m 52s
    16. Customizing the application background
      1m 33s
    17. Status bar tricks
      1m 44s
    18. Panel management options
      3m 32s
    19. Managing panels with multiple panel docks
      2m 30s
    20. Creating a panel flotilla
      2m 47s
    21. Saving custom workspaces
      3m 0s
    22. Quick spot and dust removal workflow
      3m 9s
    23. Opening a flattened version of a layered file
      2m 10s
  4. 8m 50s
    1. Tool presets
      2m 25s
    2. Resetting all tools
      1m 9s
    3. Changing the Tools panel
      1m 59s
    4. Customizing presets with the Preset Manager
      3m 17s
  5. 4m 57s
    1. Accessing the Move tool from any tool
      1m 33s
    2. Selecting layers
      3m 24s
  6. 15m 7s
    1. Selection modifiers
      4m 8s
    2. Transforming selections
      2m 56s
    3. Quick Mask is your friend
      4m 22s
    4. Viewing a selection as an alpha channel
      1m 31s
    5. Reselecting a previous selection
      2m 10s
  7. 8m 3s
    1. The lasso tools
      2m 9s
    2. The Magnetic Lasso tool
      5m 54s
  8. 9m 41s
    1. Options for the Crop tool
      1m 16s
    2. The Hide and Delete options in the Crop tool
      1m 22s
    3. Bringing back hidden pixels with Reveal All
    4. Making the canvas bigger with the Crop tool
      2m 45s
    5. Relative canvas size
      1m 9s
    6. Cropping in perspective
      2m 14s
  9. 4m 12s
    1. The Eyedropper tool
      1m 10s
    2. The Color Sampler tool
      1m 23s
    3. Straightening a crooked image
    4. Measuring an angle
  10. 5m 26s
    1. Saving file size when healing and cloning
      1m 42s
    2. Cloning from a different document
    3. Clone first, then heal
      2m 46s
  11. 7m 27s
    1. A new way to change brush size and hardness
      2m 17s
    2. Cycling through the brushes
      1m 51s
    3. Painting a straight line
      2m 2s
    4. Painting a dotted line
      1m 17s
  12. 2m 6s
    1. Cycling through gradient styles
      2m 6s
  13. 3m 34s
    1. Using fill commands instead of the Bucket tool
      3m 34s
  14. 6m 45s
    1. Options for the shape tools
      4m 2s
    2. Arrow options for the Line tool
      1m 38s
    3. Add a new shape to an existing shape layer
      1m 5s
  15. 36m 10s
    1. Point type vs. paragraph type
      2m 10s
    2. Canceling and applying text edits
      2m 1s
    3. Repositioning text while in the Type tool
      1m 32s
    4. Selecting text on a type layer
      2m 19s
    5. Renaming a text layer
      1m 58s
    6. Shift + click near an existing type layer
      1m 9s
    7. A better way to preview fonts
      3m 7s
    8. Jumping directly to the font you want
      3m 8s
    9. Changing type size and color
      3m 0s
    10. Accessing the Character and Paragraph panels
      1m 50s
    11. Type size keyboard shortcuts
    12. Kerning and tracking keyboard shortcuts
      2m 10s
    13. Leading keyboard shortcuts
    14. Alignment keyboard shortcuts
      1m 4s
    15. Changing multiple type layers at once
      1m 15s
    16. How to hang your punctuation
      1m 16s
    17. Using filters and keeping type editable
      2m 54s
    18. Checking spelling
    19. Using presets for the Type tool as styles
      2m 35s
  16. 50m 28s
    1. Converting a background layer
    2. Duplicating a layer with the keyboard
      1m 13s
    3. Duplicating a layer with the mouse
    4. Duplicating layers across documents
      2m 0s
    5. Selecting layers with the keyboard
      2m 44s
    6. Changing layer stacking order
      1m 58s
    7. Layer visibility shortcuts
      1m 31s
    8. Undoing layer visibility
      1m 34s
    9. Creating new layers
      1m 30s
    10. Creating a new layer below the active layer
    11. Locking transparency
      1m 22s
    12. Making selections from layers
      3m 29s
    13. Turning selections into layers
      4m 39s
    14. Changing the thumbnails in the Layers panel
      1m 24s
    15. Changing layer opacity
      1m 0s
    16. Changing fill opacity
      2m 9s
    17. Grouping and ungrouping layers
      1m 28s
    18. Collapsing and expanding all layer groups
      1m 52s
    19. Deleting layers and groups
      1m 4s
    20. Layer clipping masks
      3m 28s
    21. Cycling through the blend modes
      1m 57s
    22. Keyboard shortcuts for specific blend modes
      1m 25s
    23. Merging layers
      2m 27s
    24. Creating a composite copy of a layer group
      1m 48s
    25. Creating a composite copy of visible layers
      2m 26s
    26. Copying visible layers
      2m 44s
    27. Color-coding layers
  17. 18m 19s
    1. Different ways to view a layer mask
      1m 58s
    2. Toggling between a layer and a layer mask
      1m 25s
    3. Moving a layer mask to a different layer
      1m 19s
    4. Duplicating a layer mask
      1m 53s
    5. Adding a layer mask on a layer group
      2m 48s
    6. Pasting into a layer mask
      2m 6s
    7. Moving layers and layer masks
      1m 42s
    8. Inverting layer masks
      2m 9s
    9. Refine Mask shortcuts
      2m 9s
    10. Deleting a layer mask
  18. 22m 55s
    1. Working smarter by changing your keyboard shortcuts
      3m 50s
    2. Toggling the preview of an adjustment layer
      1m 10s
    3. Targeted Curves adjustments
      1m 38s
    4. Targeted Hue/Saturation adjustments
      1m 30s
    5. Adjustment layer options
    6. Cycling through channels for Curves and Levels
      1m 32s
    7. Cycling through Hue/Saturation colors
      1m 2s
    8. Clipping adjustment layers automatically
      2m 37s
    9. Starting with a selection
      2m 1s
    10. Saving time with adjustment layer presets
      3m 22s
    11. Bonus: Auto commands as adjustment layers
      3m 15s
  19. 10m 10s
    1. Options for the Curves adjustment layer
      1m 52s
    2. Setting a curve point in the composite channel
      2m 0s
    3. Setting a curve point in each color channel
      1m 58s
    4. Working with curve points
      1m 57s
    5. Accessing the Tonal Clipping preview
      2m 23s
  20. 13m 35s
    1. Scaling layer styles
      1m 59s
    2. Moving and copying layer styles
      1m 50s
    3. Creating strokes with sharp corners
      1m 16s
    4. Saving a layer style
      3m 16s
    5. Adding a watermark to an image
      2m 45s
    6. Performance tip: Hide all layer effects
      1m 1s
    7. Tricks for opening the Layer Style dialog box
      1m 28s
  21. 6m 54s
    1. Doing the Channel Walk
      3m 38s
    2. Loading selections from channels with the mouse
      1m 32s
    3. Loading selections from channels with the keyboard
      1m 44s
  22. 13m 30s
    1. Toggling the rulers, guides and grids
      2m 12s
    2. Locking and snapping
      1m 51s
    3. Changing the orientation of guides
      2m 8s
    4. Snapping guides to ruler marks
    5. Changing the measurement system
      1m 1s
    6. Using Percentage to create guides
      2m 30s
    7. Guides and image size
      1m 43s
    8. Changing the ruler origin point
      1m 27s
  23. 17m 58s
    1. Everyday modifiers for Free Transform
      1m 43s
    2. Distorting transformations
    3. Skewing transformations
    4. Perspective transformations
    5. Where are the Free Transform handles?
      1m 33s
    6. Transform Again
      1m 21s
    7. Transform Again and Copy
      1m 18s
    8. Moving the transformation center point
      1m 32s
    9. Aligning a layer to the center of a document
      1m 17s
    10. Nondestructive transformations
      3m 38s
    11. Warp transformations
      2m 47s
  24. 7m 18s
    1. Reapplying the last filter you used
    2. Reopening the last filter you used
    3. Assigning shortcuts to your favorite filters
      1m 15s
    4. Using filters nondestructively
      2m 0s
    5. Applying a filter to multiple layers
      2m 41s
  25. 10m 3s
    1. Combining files to layers from Adobe Bridge
    2. Making Bicubic Sharper the default algorithm
      2m 44s
    3. Choosing a different color ramp
      1m 9s
    4. Format multiple files with a template and variables
      5m 26s
  26. 1m 14s
    1. Goodbye
      1m 14s

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