No matter what you’ve whipped up in Photoshop, there will come a time when you need to change the size of your image. For example, if you want to print it, email it, or post it on a website, you need different-sized versions for each task. Changing an image’s size isn’t hard—Photoshop gives you oodles of options. The challenge lies in doing it without sending the image’s quality down the tubes.
Sure, you can let the “Save for Web” dialog box (Resizing for Email and the Web) or the Print dialog box (Printing on an Inkjet Printer) do the resizing for you, but if you’re aiming to be a serious pixel-pusher, you’ll want far more control. That, dear friend, brings you up against the granddaddy of Photoshop principles: image resolution—the measurement that determines the size of the pixels in the image, which in turn controls the quality of your prints.
Resolution is arguably one of the toughest digital-image editing concepts to wrap your brain around. Many people grapple with questions like “What the heck is resolution?” “How do I change an image’s resolution?” and “What’s the minimum resolution I need to print good-looking photos?” In the following pages, you’ll learn all the nitty-gritty you need to answer these—and other—questions.
Resolution doesn’t mean a hill of beans unless you’re sending the image to a printer. So if you’re not going to print it, don’t worry about resolution—focus on the pixel dimensions instead.
Pixels and Resolution
As you learned in Chapter 3 ...