FIGURE 1-5: Painting to undo with the History Brush, with the original in the upper-right.
Photoshop has another very powerful partial Undo in the Fade command. Found in the Edit menu, Fade can be used immediately after just about any tool or adjustment or filter or, well, almost anything that changes the appearance of the image. (You can even fade the History Brush tool.) The Fade command enables you to change the opacity, blending mode, or both of whatever alteration you most recently made to the appearance of your artwork with tools or commands. You might, for example, use a Sharpen filter and then use the Fade command to change the filter’s blending mode to Luminosity. That’s the functional equivalent of sharpening the L channel in Lab color mode without having to switch color modes at all. Keep in mind that when I use the word immediately, I really mean it — you can’t even use the Save command between applying a filter and using the Fade command.
Installing Photoshop: Need to know
If you haven’t yet installed Photoshop, here are a few points to keep in mind:
Install only into the default location. Photoshop is a resource-intensive program. Using the Creative Cloud Manager to install it into the default location (harddrive ⇒ Applications on a Mac and C:\Program Files for Windows) ensures that it has access to the operating system and hardware as necessary. Installing into any other location or attempting to run Photoshop across a network can lead to frustrating problems and loss of work in progress.
Disable all spyware and antivirus software before installing. Antivirus software can intercept certain installation procedures, deeming them to be hazardous to your computer’s health. That can lead to malfunctions, crashes, lost work, frustration, and what I like to call Computer Flying Across the Room Syndrome. If you use antivirus software (and if you use Windows, you’d better!), turn it off before installing any program, especially one as complex as Photoshop. You might find the antivirus program’s icon in the Windows taskbar; or you might need to go to the Start menu, choose All Programs to locate the antivirus software, and disable it. On Mac, check the Dock. And don’t forget to restart your antivirus software afterward! If you already installed Photoshop and antivirus software was running at the time, I urge you to uninstall and reinstall.
If you use auto-backup software, shut it down, too. It’s best not to run auto-backup software when installing software. Like antivirus software, it can also lead to problems by interfering with the installer.
If you have third-party plug-ins, install them elsewhere. Third-party plug-ins — those filters and other Photoshop add-ons that you buy from companies other than Adobe — can be installed into a folder outside the Photoshop folder. You can then make an alias (Mac) or shortcut (Windows) to that folder and drag the alias/shortcut to Photoshop’s Plug-Ins folder. Why install outside the Photoshop folder? Should you ever need to (gasp!) reinstall Photoshop, you won’t need to reinstall all your third-party plug-ins. Just create a new alias/shortcut and move it into Photoshop’s new Plug-Ins folder. And don’t forget to go to the plug-ins’ websites to see whether the manufacturers offer updates!
If you have lots of plug-ins, create sets. Plug-ins require random–access memory (RAM) (computer memory that Photoshop uses to process your editing commands). If you have lots of plug-ins, consider dividing them into groups according to how and when you use them. Sort (or install) them into separate folders. (Hint: Plug-ins that you use in many situations can be installed into multiple folders.) When you need to load a specific set, swap out the alias or shortcut in the Plug-Ins folder and restart Photoshop.
If you love fonts, use a font-management utility. If you have hundreds of fonts (over the years, I’ve somehow managed to collect upward of 12,000 fonts), use a font-management utility to create sets of fonts according to style and activate only those sets that you need at any given time. Too many active fonts can choke the Photoshop type engine, slowing performance. The Mac OS has Font Book built right in, or you can use the excellent Suitcase Fusion (Mac and Windows) from Extensis (www.extensis.com).
Chapter 2
Knowing Just Enough about Digital Images
IN THIS CHAPTER
In the early days of photography, some less-advanced cultures viewed a photo with great suspicion and even fear. Was that an actual person, trapped in the paper? Did taking a photo steal a person’s soul? You know that a camera doesn’t trap anyone inside the paper — and you can be pretty sure about the stolen soul issue — but how much does the average shooter know about digital images? And how much do you need to know about digital images to work effectively in Photoshop?
The answers to those two questions are “Not as much as he/she should” and “Not as much as you might fear.” In this chapter, I give you some basic information about how digital images exist in Photoshop, a real understanding of that critical term resolution, and an overview of the different ways that you can save your images. But most importantly, I help you understand the very nature of digital images by explaining the world of pixels.
Welcome to the Philosophy chapter!
What Exactly Is a Digital Image?
Whether you take a picture with a digital camera or use a scanner to bring a photo (or other artwork) into Photoshop, you are digitizing the image. That is, digit not as in a finger or toe, but as in a number. Computers do everything — absolutely everything — by processing numbers, and the basic language of computers is binary code. Whether it’s a photo of a Tahitian sunset, a client’s name in a database, or the latest box score on the Internet, your computer works on it in binary code. In a nutshell, binary code uses a series of zeros and ones (that’s where the numbers part comes into play) to record information.
So what does binary code have to do with the wedding photos that you took this weekend or the masterpiece you must print for your thesis project? An image in Photoshop consists of tiny squares of color called pixels (pixel is short for picture element), as you can see in the close-up to the right in Figure 2-1. The computer records and processes each pixel in binary code. These pixels replicate a photo the same way that tiles in a mosaic reproduce a painting.
A tile in a mosaic isn’t face or sky or grass; rather, it’s beige or blue or green. The tiles individually have no relationship to the image as a whole; rather, they require an association with the surrounding tiles to give them purpose, to make them part of the picture. Without the rest of the tiles, a single tile has no meaning.
Likewise, a single pixel in a digital image is simply a square of color. It doesn’t become a meaningful part of your digital image until it’s surrounded by other pixels of the same or different color, creating a unified whole — a comprehensible picture. How you manipulate those pixels, from the time you capture the image digitally until you output the image to paper or the web, determines how successfully your pixels will represent your image, your artwork, your dream.