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

Photo is useless without any EXIF to see what mode you were in, what flash settings etc.

Looks like you have a fast shutter speed which means no ambient in the background. Therefore the d600 has used a lot of flash power to fill the room.

Anybody who knew what they were doing would use a shutter speed that allows enough ambient in, then the flash uses low power to fill in the subject. Even if you're in one of the auto modes, you can set the flash sync speed. I set it at 1/8s for situations like this. I bet you have it set higher - maybe 1/60s which isn't enough for a room like this.

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