According to imaging resource the 6D has slightly better dynamic range and the D610 has slightly better detail.
be careful with that quote, the Canon has
slightly better DR at
higher ISO levels it says. Between 100 and 1600ISO, the D610 blows it out of the water.
View attachment 144972
That graph may be correct but imaging resource ought to correct how they worded the summary paragraph because how they worded it could be interpreted to mean overall OR only at high ISO settings.
"On paper at least, there's not much to separate the Nikon D610 and Canon 6D in the sensor department. Both have nearly-identical sensor area, and while Nikon leads by around 10% in terms of linear resolution, that difference is more modest than the pixel counts of 24.3 megapixels for the D610 and 20.2 megapixels for the 6D might otherwise imply.
Still, if you're shooting with sharp, high-quality glass and aiming for larger print sizes, the Nikon D610 has a slight edge in terms of detail, capturing around 2,700 lines per picture height in our detailed lab testing, where the Canon 6D manages around 2,400 lines. (These figures are for JPEG mode at low ISO and low compression; both cameras can manage perhaps another hundred lines of detail, if you're willing to shoot in raw mode.)
On paper, the Canon 6D looks to have a significant edge in terms of sensitivity, with an upper limit of ISO 102,400 equivalent, where the Nikon D610 tops out at ISO 25,600 equivalent. Our in-depth testing found that the Canon's higher sensitivities were of relatively little utility, however, with ISO 51,200 from the Canon 6D only capable of producing a 4 x 6-inch print, and ISO 102,400 equivalent best avoided altogether.
Crank up the sensitivity, and both cameras will of course suffer the effects of noise (and noise reduction) on image detail. Both cameras provide four-step control over noise reduction, but Canon's NR is heavier-handed, doing a better job of reducing chroma noise in particular, but at the expense of fine detail. (Again, though, if you really care about detail, shoot RAW and convert using Lightroom, Photoshop, Capture One, Bibble, DxO Optics Pro, etc)
We also looked at dynamic range of both cameras, and here there was a slight advantage for the Canon 6D over its rival. Where the Nikon D610 offered a range of about 11 stops in JPEG mode, the 6D bested it slightly with an 11.5-stop range. Switch to raw shooting, and the two were essentially tied.
Image quality, then, isn't a huge point of differentiation between these cameras. Overall, we'd probably call it for the Nikon simply because it offers slightly more detail, but JPEG shooters might find the Canon's better dynamic range and control of chroma noise at high sensitivities appealing."