D600: A gazillion EV of dynamic range isn't worth squat if your camera won't focus or meter properly Locked

I think most folks are responding based on the posters post...

It is obvious that this was user error.

There is nothing wrong with the lens or the aperture coupling as you or others have suggested or told the poster to check for. The image is correctly exposed on the subject that is in focus, the background.

Folks posting about accuracy of the metering system, focusing points, lens issue, are doing the poster a mis-service. The issue is none of these. It is that the poster used live view in a situation for which it is not intended...low light, indoors, moving subject.

A greater service would be to tell Daniel to stop using live view (it's not a point and shoot) and use the camera as it is intended. Another good suggestion is referring him to a book on how to get the most out of his D600. I don't know if Thom Hogan has published one yet or not.