I recently purchased a Meopta MeoStar S2 82mm HD spotting scope, and I have been very pleased with it. When I purchased it (from B&H) it came with a free iPhone 5/5S adapter (the same deal is still available). I decided to test it out with my iPhone 5s, not expecting too much from a camera phone. I was quite surprised what a good job it can do. I am used to using a Sony A77 with a 300mm 2.8 G Minolta lens, plus either 1.4x or 2x teleconverters. I was shocked to see my iPhone capturing pictures that were pretty comparable to the best my much bigger and heavier DSLR set-up could do.
Meopta makes similar iPhone adapters for other scopes also.
Here are a few examples taken with the scope/iPhone 5s setup:
Meopta makes similar iPhone adapters for other scopes also.
Here are a few examples taken with the scope/iPhone 5s setup: