Thanks for the thought Lloyd, but this isn't shooting with polarizer. Try switching modes while in live view and see if you get changes in how bright the image appears on the LCD. If in M, you have settings that would underexpose without the flash, the image is dark and varies, depending on the settings. With my D5100, LV seems to stay nearly the same under all the setting modes. I'm trying to get confirmation that there is a problem with my copy of the camera, and not a problem with the firmware. Can someone with D800 confirm in LV, changing the mode, does not result in a dark image in M mode, if settings on camera would under expose under ambient lighting?