I had the opportunity at the weekend to try photographing birds that were half a kilometre away, with my Canon 1DX, 500mm lens and 1.4 converter, and using my Samsung Note 4 with my Swarovski scope at 60 x magnification. We were at Lake Omanu near Foxton, and across the other side of the lake were two “white” birds, just dots to look at with the naked eye. The test was to see which would give the clearest photo for ID. Without doubt the phone/scope combination gave me the best picture, as you can see below.
PS. The camera white balance was set wrong hence the unusual colour cast in that photo.