I've had the opportunity to play around with some newer digiscoping adapters both for smartphones and for SLRs. When not using my iPhone 5s to take pictures and video, I've been using my Nikon V1, which is a very good camera and generally I use with the Swarovski TLS APO adapter.
The Digidapter is designed so you can set your camera on it and then the hood will fit over the eyepiece. Currently, this adapter will work on Swarovski, Zeiss, Leica, Kowa and Celestron. The owner is able to custom make adapters, but those will probably be a different price than what's on the website.
What I thought was cool about this Digidapter is that it fits a number of cameras--perhaps even a few point and shoots. But the really cool part is that the biggest beef I have with "universal" adpaters is that they tend to be futzy--you have to make constant adjustments. You screw the bottom of your camera to the Digidapter and then make adjustments to how it lines up with your scope eyepiece. The cool part is that the two red nuts on the adapter are adjustable and help you keep track of where to place your camera after you take it off the adapter. Once you know where your camera fits on the adapter, you slide those to the front of the camera and tighten and viola--you always know where the camera needs to go on the adapter.
If there's one downside to the Nikon V1 is that sometimes there's too much zoom with it on the scope. Which if birds are far away is great. But if you want to get birds at a feeder outside the window, you can sometimes be too close to get a full frame body shot. So I thought I would try using the V1 with the Digadapter.
I've been trying to test out these adapters at feeders to give you an idea of field of view in the camera but we keep getting cold snaps and some of my go to nature centers for photos have now covered their windows with stickers to prevent widow strikes which makes bird photography next to impossible. So I found some obliging sleeping ducks in my neighborhood.
Above is an upcropped image of a mallard taken with Swarovski ATX 95mm spotting scope, TLS APO adapter and Nikon V1. You can see that it's a challenge to get the whole bird in. I normally solve this by keeping my distance with birds and that strategy generally works out. But sometimes, like in the case of being in a blind that's not an option--isn't it always something with photography?
Above is my current system. I like it because it's relatively easy to carry in the field. To use it, I had to remove the zoom lens that came with the camera body, purchase and an adapter that would allow the body to work--funny thing, if you use a non-Nikon lens on this camera body, it won't shoot. You get an error message that says there's no lens...even though there is one. You have to spend about $120 bucks on a Nikon adapter with electronics that tells the camera body there is indeed a lens attached. You also have purchase a smaller cheater adapter that lets you actually attach another lens to it. Well played, Nikon, well played. If I'm not going to buy lenses from you, you're still gonna get some of my money.
Anyhoo, the TLS APO adapter from Swarovski has a lens inside it that is optimized to work with your scopes eyepiece. I also like that the sleeve of the adapter that fits over the scopes eyepiece also acts as a protector for the lens on the inside. I've generally liked this system and once used to working with it, you can get some really nice detailed shots (like the above caracara).
Above is an uncropped photo of a different mallard that was slightly to the left of the first mallard (it got chased off by a rival as I was switching lenses. This is with my Nikon's original zoom lens, Digidapter and Swarovski ATX 95mm spotting scope. A wider field of view than with the TLS APO adapter. But I love it's lightweight and how easily it slides on and off of my scope's eyepiece.
I think I need a different Nikon lens for this system, it's a little too close to the glass on my eyepiece than I'm completely comfortable with. There is an extender I can purchase too which takes it a little further from the eyepiece. It's a little chunkier than I'm used to, but for an adapter that works with lots of scopes and cameras, it's very good and slides on and off of the scope eyepiece easily. It's solid and made of aluminum so is fairly light weigh.