Usually your eye can see the water under the trees and move seamlessly to the blue of the sky but a camera cannot. Now Nikon can get closer than any other system but the details would simply not come out.
In the past this technique was used too in very high end photo images. High end, because it would take the better part of a day to merge three five or even seven different exposures. And while it's not a cincture, it sure doesn't take a day.