Nikon Df review: New low light champion?By Kevin Carter - Monday December 09 2013 Sensor Review
With the Df’s lower DxOMark score the D800 has the potential to offer improved image quality at lower ISO settings. Averaged out it has around a +1/3 stop advantage over the Df. Apart from the advantage in resolution the D800 has a improved color response and a wider dynamic range, though in low-light and higher ISOs the Df can claw back some that lead, particularly with noise and dynamic range where the Df is superior.
Against the Nikon D800 the Df can’t match the 36-Mpix sensor in color depth at base ISO. The new model has around - ½ stop less from ISO 100 to 200, dropping slightly, to around -1/3 stop behind the D800 from ISO 800 to ISO 25,600.
For studio and landscape, the D800 would be the better choice, though in reality there’s not much in it. Bear in mind the Sony A7R adopts the same sensor with a near identical capability as the D800, and in a much smaller, lighter weight body.
However, from ISO 800 onwards the Df has around a +1/2 stop advantage, even though the DR falls sharply at ISO3200. That +1/2 stop advantage reinforces the Df’s low light capabilities, against the D800 at least, though with other models maybe not so much.