As I've been playing with lighting and exposure with the Nikon D80, I noticed something disturbing. When looking at a photo at full 100% resolution, I saw large amounts of noise. No clean lines, no sharp edges, no solid dark colors.
This bothered me. I triple-checked my ISO setting (100) and was still seeing it. Then I happened to look at my EXIF information. My photos were being shot at ISO 1600! GAH!
Turns out that while I was specifying my ISO setting, the camera had a setting deep in the menus for Auto ISO. And it was ON.
