Whitehead Institute BaRC

Updated 7/12/05

Photoshop Tools

Move Tool

The move tool allows you to move objects. You can select layers with it, so if each of your objects is on a separate layer, this tool will move those objects just by clicking on them and dragging.

But if more than one object is on a layer, you need to first make a selection with the Marquee tool

and then move it with the move tool. This means that you must either switch tools or press the command key, which changes the marquee into the move tool. To copy a selection, press command + option. To move in a straight line, press shift. Always click the mouse button last in this sequence.


 Measure Tool .............Back to top

Lets you measure length, width, angle and location of areas in your image. If you scan something in a little crookedly, use this tool to measure the angle and then use "rotate canvas" to correct the rotation by the exact amount. To measure, choose the measure tool from the tool box. (It looks like a little ruler). Draw a line with it, and look at the info palette to see the angle, width, length and coordinates of your line. When you double click on the page, the line will disappear. Then go to Image > Rotate Canvas > Arbitrary. The amount of rotation needed to make a 90 degree angle will automatically be computed. Click OK.


Magnetic Lasso .............Back to top

For shapes that contrast with the background, this tool will snap to the edge when making a selection. Double click on the magnetic lasso icon to open the dialog box. You can set the strength of the "magnet" by entering values in the dialog box.

Frequency is the rate at which the lasso will fasten points. Enter a rate between 0 and 100. Lasso width determines how far the lasso will reach to find a high contrast edge. Enter a number between 1 and 100.

Edge contrast tells the lasso how to distinguish the desired edge from other pixels. A high value detects only images with sharp contrast to the background. A lower value detects low contrast images. On images with a well-defined border, you can use a wider lasso width and a high edge contrast, and you don't need to be precise when tracing. On a border with fuzzier edges, you should use a smaller width, lower edge contrast, and trace more carefully.

If you make a mistake and want to stop drawing, hit escape.


Freehand Pen Tool .............Back to top

This is like the pen tool in any of the other drawing programs. Anchor points and use handles to make shapes. Click and hold on the pen icon in the toolbox to see an array of pen tools. The arrowhead on the end is the vector selection tool. You can use it to select points drawn with the pen tool.

The lines themselves are vector, and won't print out. If you want to see that shape print, you need to apply a fill or a stroke to the path.

To apply a fill, click on the fill path button at the bottom of the paths palette.

To stroke a path, select the painting tool you want to use, specify a brush from the brush palette (Window > show brushes) and choose "stroke path" from the Paths palette menu (window > show paths). You can also click the stroke path button at the bottom of the paths palette. Each click of the button makes the path thicker.

This tool is also great for making a smooth selection. Just draw as you normally would with the pen tool, and then choose Make Selection from the Paths palette menu or click the make selection button.

Magnetic Pen Tool .............Back to top

Similar to the lasso tool except that it draws a line instead of a selection. Great for tracing.


Reselect Command .............Back to top

Select > Reselect. Gives you the last selection border you made in the current work session.


Transform selection .............Back to top

Now you can transform selection borders, not just images. You can rotate, reshape, and resize paths and selection borders. To do this, go to the Selection menu and choose Transform. Use the selection handles to resize the selection. When you are finished, hit return.


Grid and Guides ............Back to top

The grid helps with alignment and layout of objects, and the guides help align and crop objects. Both of these tools are found under View menu. You can choose to hide or show them. You can turn the "snapping" function on or off. (Snap means that within a set number of pixels from the guide, the object will "snap" to it).


Layers ............Back to top

Layers are like sheets of tracing paper layered over your image. In the layers palette, Window > Show Layers, you can see the layers you have created. You can only change information on the layer that is selected. Click on the eye icon at the left to make a layer invisible.


Type Layers

Any new text you enter is placed on its own layer. Each of those layers is labeled according to the text on the layer.

Adjustment Layers:

Go to the Layers palette and select "new adjustment layer" or you can also go to Layer > adjustment layer.

Adjustment layers work like filters. When you remove them from your image, the original image remains. This means you can make your tonal adjustments on layers separate from your image, so they don't become permanent until you flatten the image (merge all the layers).

To move a selection to a new layer, go to the Layer menu at the top of the screen and choose "New via Cut" or "Copy" This will either move or copy your selection to a new layer.

Aligning Layers:

Now layers (and therefore text or objects on separate layers) can be aligned individually to a selection border or to each other.

To align a layer to a selection, make the layer active, and under the layer menu, choose "align to selection". To align two or more layers to each other, first link them by selecting a layer and clicking in the box to the left of all layers you want to link to it. (You will see the linking icon appear.) Next, go to the layer menu and choose "align linked". You can use this method to align text on the page to other text or to selections. While the text is linked, you can move it as one block.


Layer Effects:

In the Layer palette you will now find a series of effects you can apply to text or other objects on that layer, such as drop shadow, glow effects, and others.


Merge Down:

This command in the Layers palette allows you to select a layer and merge it with the one beneath it. You can change the order of the layers to merge any two. Remember, though, that for adjustment layers to work, they need to be above, or higher on the list, than the original image.



Actions .............Back to top

This function allows you to record a series of actions you intend to apply to a number of files.

Creating an action:

1. Go to Window > Show Actions.

2. When you are ready to begin recording, go to "new action." Type in a name and click record. As you work, your actions will be recorded.

3. When you are finished, click "stop recording". Now you can "play" the actions from any point in the sequence, that is, apply them to another file.

Applying an action to a folder:

You can apply the recorded actions to a folder of files, and all the files will automatically go through the recorded actions. To do this, choose "batch" from the actions palette menu. It will ask you to locate a source. You can either find one on your hard drive or import files.

If at any point in your sequence of actions, you need to make a selection or plug in values you can insert a stop or a break point.

--To add a stop, choose "insert stop" from the actions palette". You can type a message to appear at the stopping point, to remind yourself of what you need to do. If you want to include a continue button, in case no adjustments are needed, check the "allow continue" button.

--To insert a break point, click in the column to the left of the action. This will pause the action so that you can type in a value, etc.

To exclude a command from the list of actions, remove the check mark at the left of the command by clicking on it.

To save a series of actions, choose Save Actions from the actions palette menu. You can then choose Load Actions whenever you want to apply those actions to a file.


The History Palette .............Back to top

The History Palette automatically records and lists everything you do in Photoshop and allows you to revisit any previous state in the list. All actions beginning with opening the file are recorded, and the most recent action is highlighted. If you want to go back to any earlier state, you can just click on that state. For example, if I decided after making many adjustments that I didn't like the way they came out, I can just go back to the step before, that, which was crop.


Linear History

Using linear history, which is the default, all the steps after crop are grayed out. I can still go back to any of those states until I begin to alter the image. When I choose a state and begin to alter the image, my alterations are saved immediately beneath the state I have chosen to work on, and the grayed out states are lost.


Nonlinear History

On the other hand, If I scroll down the History menu (arrow on the top right of the window) to History Options, I can check the nonlinear history mode. This mode allows me to go back to a previous state and work on it without losing the states that follow it. For example, with nonlinear history checked, if I go back to Crop, the states beneath it do not gray out. If I begin to work on the Crop state, my changes are recorded at the end of the list, underneath the last Adjustment Layer state.


History Brush

Working in the nonlinear history mode allows me to use the History Brush, another new tool in Photoshop 5. With nonlinear history checked, you can choose any state ( I picked Crop), select the history brush and click to the left of any other state. You can see that I have selected the second Adjustment Layer. Now I can paint with that adjustment layer on the state just after I cropped but before I made any adjustments. You can choose brush sizes and shapes by going to Window > Show Brushes.


Maximizing Space in the History Palette

The default number of saved states is 20. You can increase the amount up to 99 in the History Options dialog box. Each saved state requires lots of memory, so you probably won't want to go higher than 20. If you are short on memory, you may actually want to decrease the number of saved states.
To be efficient in saving the states that really matter, you may want to delete states from the list that you know you won't return to. For example, if I make a series of brushstrokes, each is saved separately. If I consider them all a group, I can delete all but the final one, and save room on the list for more important things.
Another way to save space in the palette is to take a "snapshot" of crucial states of my image. These are saved independently of my 20 states.


 Limitations of the History Palette

Unfortunately, the history palette is cleared when you quit the program. For this reason, it is still necessary to save your documents often. I recommend hitting command-S after each change you make. Also, before quitting the program, be sure to save any of your snapshots as separate files if you think you might want them later.


Channel mixer .............Back to top

It is often desirable to assign a separate transparent color to each of two or three images so that when you combine them, you can easily identify the areas where overlap occurs. The way to do this is to put each image on its own color channel. The Channel Mixer automates this process, and makes aligning the images much easier. Here is how to do it:

1. Open your images. They should be saved as TIFF and the mode should be set to grayscale. (Go to Image > Mode and choose grayscale if this is not already the case). If you have only two images to merge, open a third just as a placeholder.

2. Select one of the images and choose "merge channels" from the channel palette menu.( Find channel palette under the Windows menu, and then click on the arrow at the top right of the palette to see options).

3. Choose RGB color mode.


You are then able to assign a color to each of your grayscale files. Click on the scroll bars until the correct file is matched with the desired channel. If you are using a placeholder for your third file, assign it the extra color. When you are finished, click OK.



A new file will be created with your images in separate color channels.

If you are using a placeholder for a third file, you can now delete it. To do this, select the channel, click with your move tool in the work area, and choose command-a (or Edit > Select All). Then click the delete button. The next step is to fill this area with black, by selecting the entire work area with that channel selected, going to the Edit menu, and choosing Fill > with black.

Once your images are combined, you can select individual channels and use Levels or Curves adjustments on them to vary the relative brightness or contrast of that channel. If there is a lot of background noise on a channel, a Levels adjustment can bring the background back to black. (See Tonal and Color Adjustments)

Back to top