Interesting. Partly because there are software filters that people use to actively get that effect, but also partly, because I figure with software it'd be less of an issue, because people are able to take a wider shot than needed and then crop it to their desire on the computer (at least, that's what I do). Speaking of software, I've heard good things about Krita but that's more for drawing than for editing photos. The only other open source program I know of other than GIMP is LightZone which strikes me as a simplified version of Adobe Lightroom. Wikipedia has a whole list of programs, so I'm gonna do some looking into that this week as well. GIMP? I'm pretty decent at it, but I dunno, I'm stubborn in the "making things work whether or not it's easier to get something new" kind of sense. But then again, I never thought about taking photos that I really care to edit really well and now here I am.Vignetting is where the light distribution isn't even from edges to center.