iPhoto ’11: The Macintosh iLife Guide to using iPhoto with OS X Lion and iCloud

Sharpening and Reducing Noise

All digital images—whether captured by a scanner or a camera—have an inherent softness. Some softness is introduced by inexpensive lenses, and some is introduced by imaging sensors and their fixed grid of pixels.

Digital cameras compensate for this inherent softness by applying some sharpening immediately after you take a photo. You can often adjust the amount of sharpness they apply; I like to turn down the sharpness settings on my cameras, preferring to sharpen later, if necessary. (If you shoot in raw mode, your camera applies little or no sharpening to the image; see page 72.)

Inkjet printers and offset printing presses (including the kind used to print iPhoto books, greeting cards, and calendars) also introduce ...