Graphics Programs Reference
In-Depth Information
TIP
Barrel distortion is usually worst when you use wide-angle lens settings, while pin-
cushion distortion generally happens when you use a telephoto lens that's fully exten-
ded. Barreling is more common than pincushioning, especially when you use a small
point-and-shoot camera. You can often reduce barrel distortion in a small camera
simply by avoiding your lens's widest setting. For instance, if you change the aper-
ture setting from f2.8 to f5.6 (consult your owner's manual to learn how) or just zoom
in a tad, you may see significantly less distortion.
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Vignette
. If the photo has dark corners (usually caused by shadows from the camera's
lens or a lens hood), you need to spend time with these sliders. Vignetting typically af-
flicts owners of digital single-lens reflex cameras, or people who use add-on lenses with
fixed-lens cameras. Move the Amount slider right to lighten the corners or left to darken
them. The Midpoint slider controls how much of the photo is affected by the Amount
slider. Move it left to increase the area (to bring it toward the center of the photo), or
right to keep the vignette correction near the corners. Consider turning off the Show Grid
checkbox while you're working with these sliders so you have an unobstructed view of
how you're changing the lightness values in the photo. (Turn it back on again if you have
other adjustments to make afterward.)
