Electronic Resources Center: Using Photoshop

photoshop guide

Choose File > New.
A dialogue box will appear, prompting you for a file size.
First, pick a resolution. Typical monitor resolutions are 72 (Mac) or 96 (PC) ppi.
- If you plan on displaying your image on the web, you most likely will want to set your resolution at 72 dpi. For images you intend to print, see a more detailed discussion of Resolution.
Then set a size in either pixels or inches.
- Pixels are most commonly used for images on the web. Inches are easier to use for print purposes. Both systems areonly measurements and can be converted.
Choose a background. The default is white, but you may also choose transparent or set a background color.
Finally, choose a mode. The default is RGB color for 24-bit color images.
- In general, it is best to use the default mode while in Photoshop, then change modes, if necessary, before your final save. For more about colors, see Colors and Saving.
When you have specified all your settings, click OK.

To open a file:

Select File > Open.
A dialogue box will appear. In the pull-down menu at the top, navigate through the folders until you find your image.
Highlight it, and click on Open.

Retouching Images

Photoshop can create substantial enhancements or alterations to an image file. A few of the most typical steps to retouching an image follow below.

To crop an image:

Use the cropping tool (in version 5.5, this is found by holding down the marquee tool ) to drag a border around the image.
A selection border will appear, with handles at the corners.
To adjust the selection, click on one of the handles and drag.
- Note that cropping will delete all unselected area of your image. Do not continue with the crop unless you are prepared to lose this data.
To crop, press enter.
To undo the crop, go to Edit > Undo Crop. For more on undoing adjustments to images, see Common Problems.

To adjust the contrast:

Pull down the Image menu and select Adjustments.
From this submenu, select Levels.
Make sure the preview box is checked.
Drag the left and right triangles inward to where the first spikes of the histogram's color range begin.
Click OK.
You can also adjust contrast by selecting Brightness/Contrast, also located unter the Image > Ajustments menu, and dragging the contrast arrow to the left or right.

To adjust the midtones:

Pull down the Image menu and select Adjustments.
From this submenu, select Levels.
Make sure the preview box is checked.
Drag the gamma triangle (The gray triangle under the middle of the Input histogram) until the midtones look right.
Click OK.

To adjust the color balance:

Pull down the Image menu and select Adjustments.
From this submenu, select Color Balance.
Make sure the preview box is checked, and the midtones button is highlighted.
Drag the sliders to the left or right to add or subtract colors.
When you are satisfied with the effect, click OK.

To sharpen an image:

Pull down the Filter menu and select Sharpen.
From this submenu, select Unsharp Mask.
Make sure the preview box is checked, and experiment with settings. Remember that sharpening too much will pixellate the image.
When you are satisfied, click OK to apply the effects.

To smooth an image:

Pull down the Filter menu and select Blur.
From this submenu, select Gaussian Blur.
Make sure the preview box is checked, and experiment with the settings.
When you are satisfied with the effects you have created, click OK.
Remember to save your image.
To learn more about using filters, go to the section on Special Effects.

Making Selections

Photoshop allows you to select certain parts of an image and cut, copy, or paste the selection to other image files or use it as a separate layer.

To select an area by shape:

The Marquee tool lets you select areas in any one of four geometric shapes.
To use the tool, activate it by clicking on its image in the tool box.
Its default setting is rectangular; you may change this by holding down the mouse key and dragging to the right.
Then go into your image, click, and drag a marquee around your selection.
To deselect, you can either pull down the Select menu and highlight Deselect, or click anywhere outside the selection.
To copy your selection, pull down the Edit menu and choose copy, or press command-c on the keyboard.
To paste your selection, choose Edit, Paste, or press command-v on the keyboard.
To move your selection, use the move tool , and drag.
You can then drag the copied selection either to a new position in the image, or to a new file that is open. You can also create a new layer for the selection, if you wish.
If you need to select an area of equal proportions such as a perfect square or circle, hold down the Shift key while you drag the selection arrow.
To save your selection, go to the Select menu and choose Save.

To select areas by color:

The magic wand tool lets you select areas by color.
To use the tool, activate it by clicking on its image in the toolbox.
Then go into your image and click on the color area you wish to select.
To increase the selection, you can use the Grow, Similar, or Modify commands from the Select menu.
- The Grow command selects adjacent pixels of similar color, expanding the color range.
- The Similar command adds pixels of the color originally selected from anywhere else in the image.
- You can increase or decrease the scope of either of these selections by playing with the tolerance settings in the options palette.
- The Modify command allows you to expand or compress your selection by a set number of pixels.
You can also increase or decrease your intial selection by setting the Tolerance. The tolernace determines how many similar shades of color similar to the point you clicked will also be selected. A low tolerance, 0-10, will only pick up colors in a very small range. A very high tolerance (up to 255) will select most if not all of the colors in an image.
You can define what areas of your image are selected by using the Anti-Aliased, Contiguous, and Use All Layers settings.
- Anti-Aliased allows a small area around the color to be selected, creating a more even border.
- Contiguous allows only areas of color that touch each other can be selected. If you uncheck this option, all areas of your image containing the desired color will be selected.
- Use All Layers selects color from every layer of your image, not just the layer you are currently modifying.
To invert your selection, choose Inverse from the Select menu.
This option can be very useful if you wish to select a complex object from a contrasting background that is relatively monochromatic.
You can then copy, paste, move, save, or deselect as described above.

To select an area by drawing around it:

The Lasso lets you select an area by drawing around it.
To begin selecting, simply encircle an area with the lasso.
To increase the accuracy of your drawing, you can select the zoom tool and click on the area of the drawing you want magnified. To zoom out again, click while holding down the option (Alt for PCs) key.
To add to a selection, hold down the shift key while drawing around another area with the lasso . You can add either contiguous or non-contiguous areas to your selection in this way.
To subtract from a selection, hold down the option/alt key while outlining the area you want to remove with the lasso.
The default setting is the regular lasso tool; you may change this by holding down the mouse key and dragging to the right.

Use the polygonal lasso tool to draw a straight lined selection by clicking to define the ends of the line.
You can use the magnetic lasso to follow a line of color, however, this tool only works well if you have colors that are in strong contrast to each other. It is recommended that you use the magic wand in these cases.
When you have finished making a selection with the lasso, you can copy, paste, move, save, or deselect, as described above.

To clone an area:

The Rubber Stamp can be used to clone an image, or a selected area of an image.
To make a clone, press option/alt and click on the part of the image you want to duplicate; then move your mouse to the area you want to start painting, and drag to duplicate the image.

To resize a selection:

You can resize a selected area by going to the Edit menu, choosing Transform, and then choosing Scale. Four handles will appear around the selected image.
To resize while keeping the original proportions of the image, hold down the shift key while dragging the image to the desired size.
To distort the image while resizing, drag, either horizontally or vertically, without holding down the shift key.
To finalize the resizing, press enter.

To rotate a selection:

Go to the Edit menu, choose Transform, then Rotate.
Use the mouse to rotate the selection by holding and dragging on the handles .
You can also rotate by a set number of degrees by going to Edit > Transform > Numeric and typing in the degrees under the rotate box.

To fill a selection:

The paint bucket tool can be used to fill a selection with a color or pattern.
If the paint bucket is not immediately available, choose the Gradient tool and select paint bucket from the tool menu.
Under the Fill option in the bucket toolbar, select Foreground to fill with a single color or Pattern to fill with one of the available patterns.
Alternatively, you can fill a selection by going to the Edit menu, and choosing Fill.
You will get a list of options, including foreground color, background color, black, white and pattern. For more about choosing colors, see Colors.
Choose the option, opacity level, and mode you desire, then click OK.

To fill with a pattern:

Make or choose your pattern. Open a 1 by 1 file, and design your pattern, using whatever colors, tools, and filters you like; or open a pre-existing pattern you would like to use.
Select your pattern by choosing All from the Select menu to select the entire image, or making a selection from a particular area of the image.
Define your pattern by choosing Define pattern from the Edit menu.
You will now be able to fill a selected area with your pattern.
To save a pattern for future use, save it as a photoshop file, then open it when you want to use it, select all, and define pattern.

To fill using a gradient:

Choose the gradient tool from the toolbox.
Choose a foreground and background color.
Fill your selection by clicking at one edge, then dragging across while holding the mouse button down.
You can vary the look of the gradient by varying the angle at which you drag the mouse.
You can vary the length of the gradient by varying the length you drag the mouse across the selection.

Working with Layers

Building an image in layers in Photoshop allows you greater precision and flexibility since layers may be added or deleted easily.

To use the layers palette:

To activate the Layers palette, open the Window menu, then choose Show Layers. The layers palette will appear, along with the channels and paths palettes.
The image file you are working on will appear in the layers palette as the background layer.
The background layer will be highlighted, because it is currently the active layer. Photoshop will only let you work on one layer at a time.
Options for the layers palette appear at the top of the palette, the layers themselves take up the center, while icons for creating and discarding layers (a page and a trashcan ) are shown along the bottom edge.

To add layers:

To add a new layer, click on the page icon at the bottom of the layers palette, or click on the arrow to the right of the palette, and choose New Layer from the list of options.
A dialogue box will appear, in which you can name your new layer and set its mode and opacity level.
When you have made your choices, click OK.
Your new layer will be superimposed over the background or the previous layer, and will become the active layer.

To move layers:

Moving layers allows you control the stacking in your layout.
To move a layer, click on it in the layers palette, then drag it until it is positioned in the order you would like.
Let go of the mouse, and the layer will slide into the position you have chosen.
No layer can ever go behind the background. If you have covered up a background element with a layer, and would like it to reappear, you can select, copy and paste it onto a new layer.

To show or hide layers:

At the far left of the layers palette is a box in which an eye icon appears whenever a layer is visible.
If you click on an eye, it will disappear, along with the layer to which it pertains.
To make the layer reappear, click on the empty box where the eye was. Both the layer and its attendant eye will then come into view.

To copy a selection to a new layer:

Go into your file and select the area you want to copy.
Pull down the Edit menu and choose Copy, or hit command-c on the keyboard.
Go to the layers palette and make a new layer. Name it as you wish.
Pull down the Edit menu and choose Paste, or hit command-v on the keyboard.
The area you have chosen will now be a floating selection on the new layer. You can edit it as you wish while it is still selected, then deselect (command-d or Select > Deselect).

To delete a layer:

To delete a layer, simply click on it in the layers palette, drag it, and drop it into the trashcan at the bottom of the palette.

To merge layers:

Layered Photoshop files can become very large. To reduce file size and make your image easier to work with, you may want to merge the layers.
If you want to merge 2 layers, make sure that they are listed one above the other in the layers pallete, then choose Layer > Merge Down.
You can also merge all the visible layers at once, but first go into the layers palette and make sure that the layers you want to merge are visible, and the layers you want to keep separate are not.
Click on the arrow on the right hand side of the layers palette, and choose Merge Visible from the options that appear. All visible layers will now be merged into one.
Once you have merged layers, you will never be able to separate once you continue editing your image.

To flatten an image:

Flattening merges all visible layers of an image while deleting all invisible layers. It also eliminates any transparent background layer.
Go into the layers palette. Make sure all the layers you want in the flattened image are visible.
Click on the arrow on the right hand side of the layers palette, and choose Flatten Image from the options that appear. All visible layers will now be merged, and all invisible layers will be discarded.

Paths and Channels

The paths palette lets you make geometric vector drawings that are not stored as pixels within the image. The channels palette lets you separate out the colors in an image.

To use paths:

To work with paths, open the paths palette going to Window, then choosing Show Paths.
To create a path, you can use the following tools. The menu for these is found by holding down the pen tool on the tools palette:
1. The pen tool allows you to create straight lines and flowing curves and gives you the best control and precision.
2. The freeform pen tool allows you to draw a freehand path with automatic-set anchor points that you can adjust later.
3. The magnetic pen tool lets you draw a path that snaps to the edges of defined areas in your image.
4. The pen + tool lets you add anchor points to a line.
5. The pen - tool lets you remove anchor points from a line.
6. The direct-selection tool allows you to select paths or parts of paths.
7. The convert tool allows you to convert a line from straight to curved, and vice-versa.
To draw, choose the pen tool. Draw a line, or click on two separate points to create a straight line between them.
To curve a straight line, add an anchor point to your line with the pen + tool, then choose the arrow tool and drag the new anchor point.
To change a curve to an angle, choose the corner tool, and click on an anchor point on the curve.
Once you have created your paths, you can do various things to them, using the icons found at the bottom of the palette:

From left to right, they are:
1. The fill icon. Click on this to fill a closed path with the foreground color.
2. The stroke icon outlines a path with the foreground color.
3. The select icon makes a path into a selection. You can then edit it as you would any other selection.
4. The make work path icon converts a selection into a path.
5. The page icon lets you create new paths.
6. The trash-can icon allows you to discard any or all paths, if you wish.
You can save a path by double clicking on its thumbnail in the paths palette and giving it a name.

To use channels:

In the channels palette, you can modify existing color information.
To access the channels palette, Show Channels from the Window menu. All the existing channels will then appear.
As with the layers palette, visible channels will be designated by an eye icon in the left margin.
Select the area of the image you want to work with.
Click on the quick mask icon , found under the color selection area of the Tools palette. A red overlay will cover all of the image except the selected area.
To edit the mask, select a painting tool from the toolbox and paint in the selected area. Painting with black will increase the masked area, while painting with white will decrease it.
When you have masked the area you wish, click on the standard mode icon to the left of the quick mask tool. A selection border will appear around the edges of the masked area. You can then change the image in the selected areas.
If you save your selection, Photoshop will automatically put it into a new channel.

Adding Text

You may add text to any image file or layer.

To add text to your image:

Open the file or layer over which you would like text to appear, then choose the text tool from the Photoshop toolbox.
Click with the mouse in your file or layer. A dialogue box will appear, in which you can choose font, style, size, color, and alignment.
Type your text as you would like it to appear in the test area at the bottom of the dialogue box, then click OK.
The text will then appear as a new layer in your Photoshop file. While the text layer is selected, you can move it around with the move tool, and edit it however you wish (eg. fill with a gradient, apply filters, etc.).
To change your type default use the text menu found by holding down the text tool on the tools palette:

Colors

Photoshop gives you various options for selecting colors. You may also save in one of several color modes.

To choose colors:

Photoshop uses black and white as default foreground and background colors, but gives you a wide variety of options for changing colors. To examine your color options, choose Show Color from the Window menu.

The color palette will appear, with the swatches and brushes palettes appended to it. With the eyedropper tool, which is automatically activated when you choose any color choosing palette, you can choose any color you like.
To change the foreground or background color, double click on it. The color picker will appear. You can then use the sliders and the mouse to choose a new color, or place the eyedropper over the color you would like to select in your image.
To use the swatches palette, click on its title bar to activate it. Then you can choose a color with the eyedropper tool.
To add a new color to your swatches, first make it the foreground color, then activate the swatches palette. Go to the space at the end of the swatches palette (a paintbucket will appear), and click. The color will appear in a new swatch at the bottom of the palette.
To save your swatch palette for use in another image, choose Save from the options in the swatches palette.

To convert modes:

By default, Photoshop files will be created in RGB color. You may need to convert it to another mode, depending on how you will use the image. In general, it is best to convert images just before saving.
To save a color image as a .gif, you should convert it to indexed color.
To save a color image for printing, you should convert it to CMYK color.
To colorize a grayscale image, you should convert it to RGB color to activate the color palettes, then edit it with any colors you choose. Convert it to another mode, if necessary, just before saving.

Special Effects

Blending Modes & Filters

Blending modes allow you to control how the pixels in the image are affected by a painting or editing tool. Filters are used to smooth, sharpen, create distortions, or add lighting effects.

To use blending modes:

Select the paint tool you wish to use. Then select Show Options from the Window menu. The pull down menu with the following options for paint blending will appear:

Normal: Painted pixels will blend the base color with the paint color.
Dissolve: Resulting color will blend the base color with the paint color in random gradations.
Behind: This mode will work only on layers that contain transparency. It gives the effect of painting on the back of the layer, rather than the front.
Multiply: Multiplies the base color by the paint color, darkening the color.
Screen: Lightens the image by multiplying the inverse of the base and paint colors.
Overlay: Either multiplies or screens, depending on the lightness or darkness of the original image.
Soft Light: Either darkens or lightens, depending on whether the paint color is lighter or darker than 50% gray.
Hard Light: Either multiplies or screens, depending on the lightness or darkness of the paint color.
Color Dodge: Brightens the base color to reflect the paint color. Painting with black produces no change.
Color Burn: Darkens the base color to reflect the paint color. Painting with white produces no change.
Darken: Compares the original color and the paint color, and selects whichever is darker.
Lighten
: Compares the original color and the paint color, and selects whichever is lighter.
Difference: Either subtracts the original color from the paint color, or vice-versa, depending on which has the greater brightness value.
Exclusion: Similar to Difference mode, but lower in contrast.
Hue: Changes painted pixels to the chosen color, while retaining the saturation and luminosity values of the original.
Saturation: Keeps the hue and luminance of the original, while adding the saturation of the paint color.
Color: Keeps the luminance of the original, while adding the hue and saturation of the paint color.
Luminosity: The inverse of the color mode. Keeps the hue and saturation of the original color, while adding the luminance of the paint color.
Opacity: This allows you to paint with transparency.

To Apply Filters:

You can apply filters to an image, a layer or a selected part of an image.
To use filters, choose Filter from the main menu, select a type of filter (described below), then choose a particular filter from the submenu.
Each filter has its own settings to experiment with in addition to a preview box. To undo a filter, go to Edit > Undo or use the History palette.

Artistic filters: Apply a filter to your image that resembles a natural or traditional media rendition, such as colored pencil, pastels, or a sponge.
Blur filters: Soften selection or image. These filters are also useful in retouching.
Brush Strokes filters: These filters create different artistic effects like the Artistic filters, but pertain to different brush stroke and ink patterns, for example noise, edge detail, or texture.
Distort filters: Geometrically distort an image.
Noise filters: Help to blend a selection into the surrounding pixels. This is useful in removing problem areas, such as dust and scratches. Adding noise helps give a realistic look to heavily retouched areas.
Pixelate filters: These filters work by clumping pixels of similar values into larger pixels. Pointillize creates a mosaic effect.
Render filters: Create 3-D shapes, cloud patterns, refraction patterns, and simulated light reflections in an image.
Sharpen filters: The opposite of blur filters, these filters focus images by increasing contrast within the image.
Sketch filters: These filters create a hand-drawn look to your image. Most of them utilize the foreground and background colors to render the effects.
Stylize filters: These filters create a painted or impressionistic effect to your image.
Texture filters: These filters apply depth, texture, or an organic look to an image.
Video: Video filters are used to change the range of colors so they are compatible for television/video reproduction.
Other: Allows you to create your own filters (Custom), offset a selection within an image, or make color adjustments.

Automating Tasks

Photoshop allows you to automate tasks by grouping and saving a series of editing commands into an Action. Most commands can be recorded, but not all. To display the actions palette, go to Window > Show Actions.

To create an action:

First open and set up your image so you are ready to begin recording an action.
Create a new set of actions by pressing the folder icon on the bottom of the actions palette. Choose a name for your set.
Then click on the page icon.
Enter a name for your action and press the record button .
Begin editing your image as you desire. When you have completed your changes, press the stop button on the bottom of the actions palette.
Your action is now recorded under the set you named. To play your action on another image, open up that image and press play on the actions palette, for your chosen action. The new image will be processed automatically.
Note: If, in recording the "Save As" command as a step in an action, you alter the default filename that appears in the "Save As" dialog box, you may later discover that the file used to record the action is overwritten by other files on which the action is performed. To prevent this, you can choose not to tamper with the default filename assigned in the "Save As" dialog box. In cases where only the destination folder is changed in this step, the processed file name will be the same as the original file name by default. However, in an instance where the file type is changed, Photoshop may choose to save the processed file as a copy, in which case the default file name is automatically altered to include the word "copy". If this is not desirable, use either a Modal Control or Batch Processing to exercise more control over the "Save As" step. These options are described below.

To use modal controls in an action:

Modal controls are used when you wish to control aspects of a specific command, such as crop dimensions or different color values.
To apply modal controls to a command in an action, click on the box to the left of the command. The following icon will appear: .
During an action, when you reach a command with modal controls on, the action will stop and allow you to apply new settings. You then must press enter or return to execute the command.

Batch Processing

Batch processing allows you to apply an action to a folder containing multiple files, or to a series of opened images. This is useful if you have a large number of images to which you want to apply the same series of commands.
To batch process images, first be sure you have your desired action or set recorded in the actions palette.
Go to File > Automate > Batch.
Choose your set and action.
Choose your source folder by clicking on the Choose button.
For Destination, you have the following options:
1. None: Leaves the images open without saving changes.
2. Save and Close: Saves the files in their current location.
3. Folder: Saves the files in a destination folder that you must specify. Select Override Action "Save In" Commands to ensure that your files are saved in the destination folder.
Click OK to begin batch processing your images.
Note: If your action does not include a "save as" command, the Save and Close option in batch processing will automatically save the processed files by the same name and in the same format as the originals. However, if your action includes a step executing the "save as" command, always select Override Action "Save In" Commands and specify a file naming convention for the processed files which includes at least one field unique to each file (eg. original filename). This ensures that changes performed through the "save as" dialog box (such as file format changes) are performed on each file but prevents batch processed files from overwriting the file that was used in creating the action.

Saving

Save often and in multiple versions. If you have made adjustments and wish to undo them, see Common Problems. Once your image is finished, you can save it in any one of several modes and formats. Note that photoshop format (.psd) is the only format that will retain your layers.

To save in Photoshop (.psd) format:

You will want to save in Photoshop Format if you wish to keep the layers in your image for future reference.
To keep an archival copy of something originally created in Photoshop format, simply select File > Save, or command-s, making sure you have not flattened the image or merged any layers.

To save for the Web (.gif or .jpg):

To use images on the web, you will need to convert them to a web-readable format, like .gif or .jpg.
Changing formats when saving automatically flattens the image.
Go to File > Save for Web.
Under image size, select the dimensions you would like for your image in pixels. Remember to check the Constrain Proportions box if you would like to retain the proportions.
You can preview and compare different settings and file types for your image using the "2-Up", and "4-Up" tabs in combination with the zoom and hand tools, changing the settings for each preview in the dialog box to the right.
Remember to consider download time and color settings when saving your image for the web.
Save the image in the format you wish.

To save for printing:

To save an image for printing, you will first need to flatten it and convert it to CMYK color.
Before saving, go into the Layers palette and select Flatten Image.
Then, go to Image > Mode > CMYK color.
Finally, save your image as a Photoshop file.

Common Problems

A few of the most common problems with some quick and easy solutions follow.

You've made a horrible mistake:

Go to the Edit menu and choose Undo.
Or go to the File menu and choose Revert to Saved.
You can use the History palette to undo any of the adjustments you've made in sequential order. To use the History palette:
- Go to the Window menu and select Show History. This allows you to see the last 20 modifications you've made to your image.
- Using this palette, you can return to an earlier version of the image and continue working from that point. Do this by holding and dragging the tab up or down on the palette.

You've gotten a "low on memory" message:

Your image file may be getting too big (for the capabilities of your particular machine).
See whether you can merge some layers, or delete any layers or channels you are not going to use.
If you can't do anything with your image, try your desktop. Sometimes emptying the trash, or getting rid of some unnecessary files, will free up enough memory to let you keep working.

You can't save in your desired format:

Check your mode settings under Image > Mode. Changing it will change your options for saving.

You can't make adjustments to your image:

Check your mode settings under Image > Mode. If it is on 16 bits/channel, try changing this to 8.

A Final Word

If you are interested in scanning images or text or need further assistance using Photoshop, ask the Electronic Resources Center staff for assistance.

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Contents:

Introduction