Nice photo, butI don't understand:lens: 70-300mm!focal: 42mm?
D600 manual, page 217, Menu- shooting menu- auto distorsion control"Select On to reduce barrel distortion when shooting with wideanglelenses and to reduce pin-cushion distortion whenshooting with long lenses (note that the edges of the areavisible in the viewfinder may be cropped out of the finalphotograph, and that the time needed to process photographsbefore recording begins may increase). This option does notapply to movies and is available only with type G and D lenses (PC, fisheye, and certain other lenses excluded); results are not guaranteed with other lenses. Before using auto distortion control with DX lenses, select On for Auto DX crop or choose an image area of DX (24×16) 1.5× (090); selecting other options may result in heavily cropped photographs or in photographs with severe peripheral distortion."
First read, then speak!