The Nikon D600's Live View Photo mode is not WYSIWYG. Changing the aperture, shutter speed and ISO while in Live View Photo mode will not show any changes to the Live View Photo display. You won't see any change to the depth of field, blur, or noise. Changes to exposure compensation show up only within a range of +/- 3EV (or -3 to +1EV when it's dark). Many people would prefer WYSIWYG although one advantage of the non-WYSIWYG is that it's easier to work with when you are using flash and you are deleting the ambient light.
Anyhow, I found out that you can see the depth of field in Live View Photo mode. The trick is to select the aperture before you activate live view. If you do this, then the Live View image will show the actual depth of field for the chosen aperture. A couple of notes:
- After Live View is activated, changing the aperture will not show any changes to the depth of field in the Live View display.)
- If you select a narrow aperture, it will be harder for the camera to focus.
- When I want to change the aperture and see the change in DOF, I change the aperture even while LV is active. Then I just press the LV button once to deactivate it and press it again to activate it. It's smoother to me than exiting LV, changing the aperture, and reactivating LV.