I just don't understand why it would only show up on the D600 and not the D7000. It doesn't seem like the D600 just has better sensitivity. there must be something different about the physics that cause this unusual reflection.
"Cameras and lenses are simply tools to place our unique vision on film. Concentrate on equipment and you'll take technically good photographs. Concentrate on seeing the light's magic colors and your images will stir the soul." Jack Dykinga