Adobe Photoshop CC For Dummies. Peter Bauer
Chapter 3 looks at Photoshop-specific aspects of working with floating panels, menus and submenus, and tools from the Options bar, but I want to take just a little time to review some fundamental computer concepts.
Launching Photoshop
You can launch Photoshop (start the program) by double-clicking an image file or through the Applications folder (Mac) or the Start menu (Windows). Mac users can drag the Photoshop program icon (the actual program itself, with the .app file extension) to the Dock to make it available for one-click startup. (Chapter 3 shows you the Photoshop interface and how to get around in the program.)
Working with images
Within Photoshop, you work with individual image files. Each image is recorded on the hard drive in a specific file format. Photoshop opens just about any current image file consisting of pixels as well as some file formats that do not. (I discuss file formats in Chapter 2.) Remember that to change a file’s format, you open the file in Photoshop and use the Save As command to create a new file. And, although theoretically not always necessary on the Mac, I suggest that you always include the file extension at the end of the filename. If Photoshop won’t open an image, it might be in a file format that Photoshop can’t read. It cannot, for example, open an Excel spreadsheet or a Microsoft Word document because those aren’t image formats — and Photoshop is, as you know, an image-editing program.
If you have a brand-new digital camera and Photoshop won’t open its Raw images, check your Creative Cloud Manager’s Updates section to see whether a newer version of Camera Raw is available. (But remember that it takes a little time to prepare Camera Raw for new file formats. If you purchase a new camera on its first day of release, you may need to use the software that came with the camera until the next Camera Raw update is released.)
Saving your files
You must use the Save or Save As command to preserve changes to your images. After you save and close an image, some of those changes may be irreversible. When working with an important image, consider these tips:
Work on a copy of the image file. Unless you’re working with a digital photo in the Raw format (discussed in Chapter 6), make a copy of your image file as a backup before changing it in Photoshop. The backup ensures that should something go horribly wrong, you can start over. (You never actually change a Raw photo — Photoshop can’t rewrite the original file — so you’re always, in effect, working on a copy.)
Activate auto recovery. In Photoshop’s Preferences ⇒ File Handling panel, make sure that the Automatically Save Recovery Information Every option is selected and set to an appropriate time interval. If Photoshop crashes while you’re working, when you reopen the program, it will (hopefully) be able to present you with your artwork at the stage when last saved for auto recovery.
Save your work as PSD file, too. Especially if your image has layers, save it in Photoshop’s PSD file format (complete with all the layers) before using Save As to create a final copy in another format. If you don’t save a copy with layers, going back to make one little change can cost hours of work.
If you attempt to close an image or quit Photoshop without saving your work first, you get a gentle reminder asking whether you want to save, close without saving, or cancel the close/quit (as shown in Figure 1-4).
FIGURE 1-4: Photoshop reminds you if you haven’t saved changes to an image.
Keyboard shortcuts
Keyboard shortcuts are customizable in Photoshop (check out Chapter 3), but some of the basic shortcuts are the same as those you use in other programs. You open, copy, paste, save, close, and quit just as you do in Microsoft Word, your email program, and just about any other software. I suggest that you keep these shortcuts unchanged, even if you do some other shortcut customization.
Photoshop’s incredible selective Undo
Here’s one major difference between Photoshop and other programs. Almost all programs have some form of Undo, enabling you to reverse the most recent command or action (or mistake). Photoshop also has, however, a great feature that lets you partially undo. The History Brush tool can partially undo just about any filter, adjustment, or tool — by painting. You select the History Brush, choose a history state (a stage in the image development) to which you want to revert, and then paint over areas of the image that you want to change back to the earlier state.
You can undo as far back in the editing process as you want, with a couple of limitations: The History panel (where you select the state to which you want to revert) holds only a limited number of history states. In the Photoshop Preferences ⇒ Performance pane, you can specify how many states you want Photoshop to remember (to a maximum of 1,000). Keep in mind that storing lots of history states takes up computer memory that you might need for processing filters and adjustments. That can slow things down. The default of 50 history states is good for most projects, but when using painting tools or other procedures that involve lots of repetitive steps (such as touching up with the Dodge, Burn, or Clone Stamp tools), a larger number (perhaps as high as 200) is generally a better idea.
The second limitation is pixel dimensions. If you make changes to the image’s actual size (in pixels) with the Crop tool, the Image ⇒ Crop command, or the Image Size or Canvas Size commands (both in the Image menu), you cannot revert to prior steps with the History Brush tool. You can choose as a source any history state that comes after the image’s pixel dimensions change but none that come before.
Here’s one example of using the History Brush as a creative tool. You open a copy of a photograph in Photoshop. You edit as necessary. You use the Black & White adjustment on the image to make it appear to be grayscale. In the History panel, you click in the left column next to a snapshot (a saved history state) or the step prior to Black & White to designate that as the source state, the appearance of the image to which you want to revert. You select the History Brush tool and paint over specific areas of the image to return them to the original (color) appearance (see Figure 1-5). There you have it — a grayscale image with areas