Our latest test scene is designed to simulate both daylight and low-light shooting. Pressing the 'lighting' buttons at the top of the widget allows you to switch between the two. The daylight scene is shot with manually set white balance, but the camera is left in its Auto setting for the low-light tests.
As you might expect, the Df can't compete with its peers in terms of resolution - 20, 24 and 36MP cameras are now the norm at this level, so the Df looks a bit out of place in that contest. However, the performance is certainly credible.
It's as the sensitivity rises that the Df begins to show its full capabilities. At ISO 1600 the Df does a really good job of retaining convincing low-contrast detail. Part of this is down to its JPEG engine (you can see the D610 does a similar job, but with a little more blurring as it tries to suppress its slightly higher noise level).
By ISO 12800 the Df is able to maintain much better detail than its rivals (note, in particular, the heavily smoothed JPEGs of the EOS 6D), though there are hints of chroma noise creeping into the shadow on the left-hand-side of the subject's face. Switching to Raw mode shows how much less noise the Df is producing - explaining why the JPEG engine has an easier time. Comparing the cameras at a common output size reduces the extent of the difference, with the EOS 6D producing a result that's closer to the Df's standard than either the D610 or Alpha 7 can match.