Falloff

When the edge of the picture gets darker

Photography is all about collecting light. Ideally you want that light falls equally on all parts of your sensor. This is not always easy. Especially with fast lenses at larger apertures, the corners may get a bit darker.

Problem at larger apertures

This is a problem that is more pronounced at larger apertures, and when it starts bothering you it can easily be compensated by decreasing the aperture.

Two main distortion types

These pages are for Amateur Photographers and not really for seasoned photographers and professionals. I have no affiliation or commercial interest with any brand/make. I write from my own experience. I ended up using mainly Nikon, so I am more familiar with this brand than others. See price for notes on pricing as well as photography related links.