While trying out the Nikon D500 I wanted to see how good (or bad) the noise was at high ISO. What I found was the noise at 51200 was not as bad as I expected. There is obviously a lot of noise but it was very smooth and even. Quite frankly its still usable, especially if you're shooting low light sports.
Download the DNG files below to check out 25600 and 51200 for yourself.