We shoot a specially designed chart in carefully controlled conditions and the resulting images are analysed using DXO Analyzer software to generate the data to produce the graphs below.
A high signal to noise ratio (SNR) indicates a cleaner and better quality image.
For more more details on how to interpret our test data, check out our full explanation of our noise and dynamic range tests.
JPEG signal to noise ratio
In terms of the JPEG images, separating out most of the cameras on this test is very difficult, with extremely similar results from the D4S, D4, Nikon Df, and the Canon EOS 1Dx for signal to noise ratio. The Sony Alpha 7R, which also uses a full-frame sensor is the worst performer on this test here, and it isn't capable of shooting the very high ISO values that the others can.
Raw signal to noise ratio
In this chart for signal to noise ratio for raw format (after conversion to TIFF) files, we can see the D4S putting in a good, consistent performance across the sensitivity range, coming out on top for the lower values (ISO 100 - 400) and matching very closely with the Df across the range. Towards the higher end of the sensitivity run (ISO 1600 and above), the D4s just slips behind the D4 and the Canon EOS 1Dx. This could be down to the camera favouring detail reproduction of noise reduction.
JPEG dynamic range
Again, the D4S puts in a good, consistent performance here for JPEG dynamic range. At the lower end of the sensitivity scale, the D4S is very closely matched to the other cameras on the test, beating the Canon EOS 1DX with the most significance. As the ISO number raises, performance drops, as we'd expect, but it is only the 1DX which marginally beats the D4S throughout the range.
Raw dynamic range
In terms of the raw format files (after conversion to TIFF), the D4S once again performs very well. Here we can see that the Sony Alpha A7R is actually the best performer at the lower end of the sensitivity scale, but other cameras including the D4S, D4 and Df are very close behind. The Canon EOS 1DX is the worst performer at the bottom end of the sensitivity run, but it beats the other cameras on test at the very top of the range.