On 16 Dec 2001 12:42:16 -0600, "Tekn0" <123@abc.com> wrote:

>What is "Vignetting"?

Blocking of the image due to an intervening
object... Remember those old photos with the
corners darkened by a mask placed in front of the
lens (that cuts off part of the image)? Same in
video, caused by internal structure, or by a
too-thick filter rim, or by a shade with too
small a front for its length, or by whatever
might be in the way of transferring part of
the subject's the image to the CCDs...
Related in effect (image corner darkening) is
"uneven illumination", but that is generally
caused by optical problems...