The Nikon D850 looks to be even better then the D810 at reducing noise at High ISO's. This will be incredible for those who shoot a lot in the dark. Shooting concerts, weddings, the Milky Way and so much more, will now look so much better.
Look at these results that Bill Claff has provided.
http://www.photonstophotos.net/Charts/RN_ADU.htm#Nikon D810_14,Nikon D850_14
Look at these results that Bill Claff has provided.
http://www.photonstophotos.net/Charts/RN_ADU.htm#Nikon D810_14,Nikon D850_14