In this wonderful world of digital imaging, you see resolution used in four basic ways:
Image resolution: Image resolution is the size of your image’s individual pixels when you print. I go into greater detail about this concept in the upcoming section, “Picking an image resolution.”
Camera resolution: Digital cameras capture each image in a specific number of pixels. Check your camera’s user guide or open one of the images in Photoshop and choose Image? Image Size. Take a look at the number of pixels that your camera records for the width and for the height. Multiply the numbers together, divide by one million, and round off the result. (If you’re in the camera maker’s marketing department, make sure that you round up.) That’s the megapixel (MP) rating for the camera. Use it as a general guideline when shopping. If you create Web graphics or snapshot-size prints, 3 or 4 MP is fine. For large prints, you need at least 6 MP.
Monitor resolution: Monitor resolution determines how many pixels are visible on-screen. Whether you use a Mac or a PC, you set the monitor resolution at the system level (as shown in Figure 2-4). When you use a higher monitor resolution, you get a larger workspace, but each pixel is smaller, which might make some jobs tougher. Experiment to find a monitor resolution that works just right for you.
Mac: Click the blue Apple menu in the upper-left corner of the screen and choose System Preferences. Then click Displays. (Some Apple monitors have a button on the bezel that automatically opens the window for you.)
Windows: Choose Start?Control Panel and then double-click Display. Click the Settings tab to see what monitor resolutions are available.
Printer resolution: Unlike the three preceding terms, printer resolution doesn’t involve pixels. Rather, a printer resolution tells you how many tiny droplets of ink are sprayed on the paper. Remember that it takes several droplets to reproduce a single image pixel — you certainly don’t need an image resolution anywhere close to the printer’s resolution!
(See the following section for more on this.)