I recently modified an universal camera mount, intended to mount a camera to a telescope eyepiece for afocal photography (never use). I modified the mount to securely hold a smartphone to a telescope eyepiece for afacal astrophotography.

During last month's Lake Fort Smith Star Party, I tried to use the un-modified camera mount
with my iPhone, to take pictures of an American Eagle that we spotted, and the Moon. It worked slightly but was very shaky and wouldn't hold the iPhone in the eyepiece "Sweet Spot".

I took universal camera mount apart and attached a part from a iPhone car window mount with a 1/4" knob bolt from a hardware store.

This setup works great!!!

The modified mount holds the iPhone securely and doesn't move when you touch the iPhone.

It works very well with the standard camera app on the iPhone.

The next thing I discovered was an iPhone Photo app that, wirelessly via Bluetooth, send the live image from one Apple device to another. The app name is " iWatcher Pro ". I think it was $1.99 in the Apple App Store, but they do have a free version with less capibilities.

I can install the iPhone on the telescope, then start the app on the iPhone as a remote camera. Then I start the app on my larger iPad and set it up as a monitor. I will mount the iPad on either a photo tripod or car window mount on my SUV. This will provide star partie attendees a full screen iPad high resolution view of what is in the telescope.

The iPad also acts as a remote control to take photos or start recording videos on the iPhone.