Pics taken with Nikon D70s, Tokina 12-24mm


12mm 1s f/16 ISO 200.  No flash.  Tripod and self-timer used.
I converted the pic from NEF to JPG and resized.  No other editing was done.
Note the black band.


Same settings as in above pic.  In this second attempt there is no band.

Is this a shutter problem?  A mirror problem?

I have posted this question in this newsgroup: rec.photo.digital.slr-systems.
Question title: Bottom 20-percent D70s image dark