I upgraded to a used Nikon D800 a couple weeks ago. I haven't used it much yet due to the weather being garbage here, but I've been going through the manual and familiarizing myself with it a little. I rarely shoot digital, so it's a relatively new world to me still. Right now I am just using my old manual F mount lenses (Nikkor 43-86, Vivitar 28, Vivitar 80-200), as the camera didn't come with a lens. While I do plan on picking one up in the near future, I've noticed my current lenses are vignetting, sometimes quite a lot. I've done a bit of reading and I understand this is normal, but I still don't totally understand why—these are lenses that don't noticeably vignette on my 35mm cameras, and the sensor in the D800 is the same size. Can anyone explain this to me like the optics dummy I am? I also would like to know how I can avoid or fix this in-camera, if there is a way. I don't like spending a lot of time in photo editing software in general, and don't want to be cropping out vignetting in every shot I take. And one last question—are there any AF lenses that would have less of this issue, so I know what to keep an eye out for? I'm probably only going to buy one, either an ~80 prime or a ~28-80 zoom.