vignetting
A reduction (or more rarely, an increase) of an image's brightness or saturation at the periphery compared to the image center.
For a hard-edge circular border, use round border instead.
h4. Examples
* !post #7149829
* !post #7379833
h4. See also
* Backlighting
* Peeking
* Tag group:Image composition
h4. External links
Aliases: none