The Adobe Photoshop Layers Book
Harnessing Photoshop's Most Powerful Tool, covers Photoshop CS3
By Richard Lynch
Focal Press Copyright © 2007 Richard Lynch
All right reserved.
Chapter One The Basics of Layers: Layer Functions and Creation
Understanding how to work with layers starts with understanding some basics about what layers are, what their capabilities are, what functions are in the layers palette, and how to locate all that you need to apply basic layer power. In this chapter we explore the layers palette, see how all the basic layer functionality fits into the layers palette and menus, learn how to create layers, access and apply basic layer functions, and look at how to adjust the layer viewing preferences. We'll run through a hand's-on no-knowledge-necessary example of using layers and see some simple effects that can be achieved in the world of layers. Even if you feel comfortable with layers, this chapter will help make sure we are all starting off with the same basic familiarity with layers and how they are accessed as tools. With that under our belt, we can look forward to applying layers to images.
What is a Layer?
Images are usually considered to be two dimensional. That is, when images get printed on a piece of paper or displayed on a screen, they have a height and width only. Although there may be an appearance of depth, there is no actual depth. The images are flat, and lack a third dimension.
Whenever you view images fresh from a digital camera, the image is flat and two dimensional on your screen. This is true, even though the image may actually be stored as separate Red, Green and Blue (RGB) grayscale components in the file (see Figure 1.1).
The components of your RGB image that are combined by the computer when the image is displayed, and the result is a two-dimensional color image rendered on your computer screen.
Layers are similar to RGB color components, in that multiple layers can be added to an image and the result is still an image in two dimensions. Layers act as additions to your image that overlay one another as you add them to the layer stack (see Figure 1.2). These additions can be full color as opposed to grayscale RGB components. When an image with layers is displayed in Photoshop (or Elements and other programs that can recognize images stored with layers) the result is still a two-dimensional image made from a composite of the layers (see Figure 1.3). Individual layers can store complete RGB color that will combine in two-dimensional display of the image, as if you were looking down through the layers from the top of the layer stack.
Adobe called the virtual stacking of images 'layers' because they resemble a layered stack of transparent images. New image content is added to the original image and creates alterations to the image by layering, or building on changes over the original image content. It does this without changing the content below the new layer. This ability to make additions to the image in layers keeps changes and alterations more fluid and movable, allowing you to finesse and sculpt the image result.
Layering allows you to work on distinct image areas while retaining original image information in the layers and background below. This ability to retain original image information is known as non-destructive editing; you retain the original image information undisturbed as you make changes by adding image layers. Each change is incorporated as if they were made on transparent sheets over your image that can be removed or re-ordered. The layers are stored separately in the working image file and when saved to layer-friendly formats (TIFF, PSD, PDF). During editing, layer content can be viewed and managed using the Layers palette (see Figure 1.4).
Layers can be created as needed and used for infinite adjustments to your images, and they can be stored with the image, copied both in the current image and to other images. They can be adjusted and revisited for further changes at any time. Each layer is a distinct visual object that can fill the entire image plane, though the visibility of individual layers and layer content is affected by many other layer properties such as layer mode, layer opacity, layer masking, layer clipping and layer visibility.
While the basic functionality of layers is simply allowing you to keep image content and changes separate, the separation allows you the advantage of customizing how image areas combine. Control gives you advantages that allow you to achieve results that would otherwise be impossible or extremely difficult in an image without layer capabilities. Each of these capabilities will be explored through the examples and exercises in this book.
Layer Palettes and Menus
One of the keys to making use of layers is knowing how to access layer functions. Layer functionality can be found in several places in Photoshop, with the bulk of layer functions found between the layer palette, the layer palette menu, the Layers menu and Layer Styles.
The layers palette (see Figure 1.5) is really a command center for controlling layer views and how layers combine. Open the layers palette by choosing Layers from the Windows palette.
Simple buttons on the palette allow you to access many powerful features at a click. For example, you can toggle the visibility for individual layers on or off, you can add effects, create new layers, duplicate layers and delete them. Other button features allow you to lock layer transparency, color and transparency, position, or the entire content of the layer (transparency, color and position) (see Table 1.1).
Photoshop's Layer Palette Menu and Layer menu share much of the same functionality with a few exceptions depending on the current editing task. Both menus are context sensitive, adjusting functions and function availability depending on what features can logically be applied. Options are grayed out when not available. While functions on the menus represent the same things, access to those functions may affect how layers are created and handled in the image.
It is not necessary to memorize the functions and menus, there will be layer functions you rarely use and those you will perhaps never use. The graphic reference to the functions (Figure 1.5) will prove to be a handy guide if you are not very familiar with layers. What is more important than memorization is to know what type of functions are available and generally where they can be found and what type of access the program provides to those functions. That way even if you don't know the exact tool or function, you at least know where it can be located. Rolling over tools and icons in Photoshop will reveal tool tips that name the item/function, and using these actively in the program as you edit will help you get familiar with all the functions in context.
There will be occasional mention of version-specific features in exercises (including features in newer Photoshop versions), however, in most cases if you are using an older version, it will not impact working with your images or completing the exercises from this book or using the book's technique.
Types of Layers
There are several distinct types of layers that can be created in your images. All are visible in the layers palette, though some (Adjustment Layers, for example) have no visible content though they affect change in the image. The types of layers are listed in Table 1.2.
The distinction between Background and normal layers is an important one. Background layers serve a distinct purpose as the image background and lose a lot of the functionality of free- floating layers. Certain tools will behave differently when applied to backgrounds and others cannot be applied at all. For example, the Eraser tool will erase to the background swatch color rather than transparency as it would in other layers. Similar masking issues apply: you cannot apply a layer mask to the background layer.
The above reference is just a quick look at the vast capability of layers. Hands-on experience with layers in realistic situations will familiarize you better with how to look at and control layer content and the advantages they provide for editing images. Before getting into creating your first layers, let's take a quick look at controlling what you see on the layers palette using the Layer Viewing Preferences, and then we'll practice making a few layers.
Layer Viewing Preferences
Layer viewing preferences determine how you see thumbnails in the layers palette. These preferences are set on the layer palette menu. To get to the layer palette menu, you will need the layers palette open; it may help to have an image open as well so you can see the difference in the setting results.
Try It Now
1. Open any image in Photoshop.
2. If your Layers palette is not already in view, choose Layers from the Window menu.
3. Click on the menu button at the upper right of the palette.
4. Choose Palette Options from the menu that appears. The Layers Palette Options dialog will appear (see Figure 1.6).
5. Choose your preference for the size of the thumbnail that you prefer to view.
Either the second or third option from the top is recommended for thumbnail viewing. This will allow you to get an idea of layer content without taking up too much of your screen. No view will prove to be completely adequate when trying to distinguish layers. While the largest thumbnail gives the best view of the layer content, it may prove to be too large for many of the exercises in this book as the layers will cascade off the screen. The 'None' option will take up the least amount of screen landscape, but will make you rely entirely on layer naming which negates the value of visual cues.
You can change this option at any time; it applies to the palette, and not to actual layer content.
Getting Started Creating Layers
There are many ways to create new layers in Photoshop, and the methods serve different purposes. Table 1.3 describes various methods, and the most common ones.
Try It Now
If you take a moment and sit down in front of the computer and run down the bullet list, you can test out creating all these new layers. Of course there are reasons to create layers, but right now gain some familiarity with the basic creation methods. This will help you locate them later when you need them, and play is a great way to become familiar and comfortable with creating layers. It won't be long till we are immersed in serious layer work!
If you do go through the exercise of creating the layers, you'll notice that different layer types can be identified by different layer icons in the layers palette. Table 1.4 shows icons and what they mean.
At this point we have dissected enough of the layers palette and the things that you will see there to have a reasonable orientation as to what to expect.
Running through the bullet list and creating random layers in a stack may be interesting, but not nearly as interesting as working through a practical example. In this exercise, we will take an image, add a copyright, burn in the frame, and add a drop shadow using some simple layer creation and techniques. The exercise is a fairly easy, more or less practical run-through of some layer creation techniques that will take about 15 minutes and requires little or no understanding of layers. This is meant to be a glimpse into layer functionality; while there is some explanation of what is going on during the exercise, better understanding of the features we are looking at will come as we explore the possibilities of layers throughout the rest of the book.
There is almost always more than one way to execute a set of steps to accomplish a result in Photoshop. Though you may usually use different methods, even for simple steps, it is suggested that you follow the steps as written the first time you run through any exercise in this book - especially when a specific means of accessing a function is suggested. Experimenting with other methods may yield somewhat different or confusing results. If an option or function step is not specifically mentioned, it is left up to you to choose.
Try it Now
1. Open any image and flatten if necessary (Layer>Flatten Image). The image should have only a Background layer when viewed in the Layers palette.
2. Double-click the Background layer. This will open the New Layer dialog (see Figure 1.7).
3. Change the layer name of the Background Copy layer to '1 Original Background' by typing in the Name field. Click OK to accept the changes (Figure 1.8).
4. Set the background swatch color to white. To do this press D on the keyboard (sets default colors). This color selection will affect the results of the next steps.
5. Create a new layer (click the Create a New Layer button on the Layers palette). This creates a new layer above the 1 Original Background layer.
6. Make the new layer into the background layer by choosing Background From Layer (Layer>New>Background From Layer). This will change the layer to a background and fill with white.
7. Choose Canvas Size from the Image menu. When the dialog appears, choose the following options: New Size: Width: 120% (Choose from the menu in the dialog box), New Size: Height: 120%, do not check the Relative box, leave the anchor (White box in center) at the default, Canvas Extension Color: Background. Click OK to accept the changes. This will create a white border around your image.
8. Choose the Type tool by pressing T on your keyboard.
9. With the type tool selected, choose a font and font color for a copyright from the Options bar. If you don't know what to choose, pick Arial, Regular, 12pt and black. These options can be found on the Options bar, just below the program menu.
10. Click on the 1 Original Background layer in the layers palette to activate it and then click on the image with the type tool. This will create a new type layer in the layers palette just above the 1 Original Background layer, and a blinking cursor will show on the image.
11. Type in ' 2007 [your name]', click the Commit Any Current Edits button on the Type Options bar, and move the copyright to a place in the image that seems suitable using the Move tool. To choose the Move tool, click the Move tool on the toolbar, or press V on your keyboard.
Excerpted from The Adobe Photoshop Layers Book by Richard Lynch Copyright © 2007 by Richard Lynch. Excerpted by permission.
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