I own a D800 and have been happy with it. I use it for UW photography in an aquatic housing. I recently noticed a shadow edge at the under site of the image. see pic attached. At first I thought it was due to the fast sync speed 1/320 sec I was using but now it is even happening at 1/250 sec.
typical settings AF-C 3D iso250 F32 on a 105mm with Kenko 1.4 tele-converter.Strobe YS-D1 slaved off the pop-up flash