I like to think of Photoshop as the “bachelor’s” software. Many of its editing features never require you to make a commitment. While the bachelor (or bachelorette) may frustrate his or her paramour, Photoshop’s independence is a virtue in that by not committing to an edit means that you can never make a mistake. All this sounds flaky, but, believe me, a lack of commitment in image editing (unlike relationships) is a good thing and a vital component to a dynamic workflow.  

There are several features in Photoshop and all of Adobe’s graphic arts software that perform in a non-linear modality. Image components can be accessed at any time and altered or converted back to a former state with little effort and without affecting other elements. There are several features that support a dynamic workflow including: Alpha Channels, Layers, History, Adjustment Layers and Smart Filters.

Figure 1: The Channels palette with an Alpha Channel: its purpose is to store Selection Masks.

SAVING ALPHA CHANNELS

Let’s start with selections. Making an accurate selection is critical to performing a credible edit. Perhaps you want to fill several areas on an image with a color. Precisely selecting numerous areas and refining their edges can be a time-consuming process that you only will want to perform once. You may find that later in the image-editing process the color you filled the selected areas with isn’t quite on the money. Saving the selection as an Alpha Channel will enable you to reactivate it at any time. It’s a simple and fast form of insurance. Just click on the Save Selection as Alpha Channel icon in the Channels panel, and the selection will be stored as Alpha 1 (see Figure 1). The channel’s thumbnail will be displayed in the Channels panel. The black areas on the thumbnail represent areas on the selection that are masked, and the white areas represent the areas that will be affected when you perform the edit. To load the alpha channel as a selection at any time during the editing process, drag it to the Load Selection icon in the Channels panel, and the selection outline appears in the image window ready for editing.

Figure 2: A layer mask reveals or conceals layer content and can be edited at any time.

Figure 3: Like a layer mask, a vector mask conceals content. Unlike a layer mask, it is defined by Bezier curves.

CREATE LAYER CONTENT

Workflow-wise, copying or cutting content to layers is the only way to go. There are several advantages to saving image content to layers. For one thing, the layer isolates elements, so they can be repositioned at any time. If you duplicate the layer and then turn off the original layer’s visibility icon, you can apply a transformation, like scale, rotate, distort, etc., independent of the rest of the image. If later you decide you wish you hadn’t transformed the elements or you want to modify the transformation, you can discard the transformed layer and begin again on the original.  You also can apply and change blending modes and opacity on layer content to enhance color. Similarly, layer styles, those cool canned effects, can be applied and modified at any time, too.

TWO DYNAMIC MASKS

Layer and vector masks are features that affect visibility of image elements. A layer mask (see Figure 2) works like a non-destructive eraser. Painting on a layer mask with black conceals layer content. Painting on the mask with white erases the black areas and reveals the content. Painting with gray produces levels of translucency, depending on how dark or light the gray is. You don’t need to permanently erase or cut content when layer masks conceal and reveal the elements and preserves them so that you can later alter their position or shape.

Like layer masks, vector masks work in a similar manner, except they are created with paths to define their edges. You can edit the shape of a path with the Path Selection and direct Selection Tools to reposition its Bezier curves. In the Layers palette, the vector mask thumbnail uses gray to represent areas that are masked and white to represent areas that are visible (see Figure 3).

Figure 4: Photoshop CS4’s new Adjustment panel automatically generates adjustment layers.

Why would you consider permanently erasing or cutting image content when you have the ability to neatly conceal and reveal with layer and vector masks?

DYNAMIC ADJUSTMENTS

Color and contrast adjustments are inevitable on most images. Applying an adjustment directly to a layer is ill-advised because it alters the numerical values of pixels. It may be quite difficult, if not impossible, to return to the original values, especially if multiple adjustments have been applied. With adjustment layers, the color and contrast modifications are reversible and completely editable. In Photoshop’s latest version, CS4, adjustment layers can be generated from the new Adjustment panel (see Figure 4). Click on one of the adjustment icons and an adjustment layer is automatically created. The panel displays the adjustment controls. If later during the editing process you decide to modify the adjustment, click on the adjustment layer icon in the Layers palette, and, once again, the controls are displayed on the panel. Drag sliders, check boxes or type new values to change the contrast or color of an image.

Figure 5: A Smart Filter can be applied and later faded or reapplied.

Figure 6: The History palette lets you interactively backtrack to a former state of the image.

Adjustment Layers are accompanied by layer masks to partially or totally conceal the effects of the adjustment on specific areas of the image. The overall strength of the adjustment can be altered at any time by dragging the opacity slider.

APPLY SMART FILTERS

Filters can also be dynamic. If you convert a layer to Smart Object (select the Layer and choose Layer > Smart Objects > Convert to Smart Object) you can apply a filter effect as a Smart Filter (see Figure 5). The effects of Smart Filters are completely editable. You can control the strength of the filter effect after it’s been applied with fade sliders that you access on the layers palette. By dragging the sliders, you gradually blend the effect with dynamic sliders. Like an adjustment layer, you can click on the filter’s icon in the layers palette and redisplay the filter’s controls so you can change the settings at any time during the editing process. If you decide that you don’t like the effect, it’s a simple matter to delete the smart filter thumbnail from the Layers palette. Like an Adjustment layer, a Smart Filter automatically generates a layer mask to fully or partially conceal the effects of the filter on the image.

HISTORY

The most dynamic of all of Photo-shop’s features and the one that assures a flexible workflow is the History panel. As you edit your image, every command, tool application or menu item you initiate is recorded in a list of “states” in the History palette (see Figure 6). At any time, you can click on a state, and the image window will display the image as it was after the command had been applied. The default number of states is 20, but you can add more by designating a new value in the General Preferences dialog box, but be careful—too many history states consumes memory, which ultimately can compromise performance.

Instead, it’s advisable to make a “snapshot” of the image at key intervals in the editing process. Click on the Snapshot icon (it looks like a camera) at the bottom of the Layers palette. If you reach a state in the editing process and are dissatisfied with what you’ve done, click on a snapshot to revert back and continue editing.

The History Brush tool will edit specific regions of the current image back to a former state for maximum flexibility. These features create an extremely dynamic workflow. The bad news is that History is recorded for only the current work session and is not saved along with the file. You can, however, save any snapshot or history state as a document, thereby, generating multiple versions.

Considering the amount of time and effort that goes into most well-edited images, working dynamically is not only wise—it’s essential. Photoshop is insurance against errors and makes your experience as rewarding as possible with a minimum of effort. Learn to use these features. They are well worth the time it takes to feel comfortable in the non-linear environment and will ultimately streamline your workflow, which means less time at the computer.