How do I install the Starlight Instruments 3.0" Adapter on my AT106?
Installation involves unthreading the stock focuser from the rear cell of your Astro-Tech AT106 telescope. This adapter then threads directly onto the exposed M113x1 threads on the optical tube, providing a secure base for your 3.0" Feather Touch focuser. Always consult your telescope's manual for instructions on removing the original focuser.
Will this adapter work with any 3.0" Feather Touch focuser?
Yes, this adapter is specifically designed to be the mechanical interface between an Astro-Tech AT106 optical tube and any Starlight Instruments 3.0" Feather Touch focuser, such as the FTF3015B-A or FTF3025B-A models.
Why is a threaded adapter like this M113x1 model better for imaging with my AT106?
A threaded connection is critical for astrophotography because it creates a single, rigid unit from your telescope to your camera. This prevents any possibility of sagging or tilting, known as system flexure, which can cause elongated stars at the edge of your field. For an imaging setup on an AT106 with a heavy camera, filter wheel, and off-axis guider, a threaded connection is essential for maintaining optical alignment.
Does this adapter add to the back focus of my AT106 imaging train?
This adapter is designed to position a 3.0" Feather Touch focuser at the correct distance from the optical tube. The adapter itself has a specific mechanical length that becomes part of your overall back focus calculation. It is always critical to measure the total back focus of your specific imaging train after installation to ensure your camera sensor can reach focus.
Can I use this adapter to mount a 2.5" or 2.0" Feather Touch focuser on my AT106?
No. This adapter has a 3.0" opening and bolt pattern designed exclusively for the 3.0" series of Feather Touch focusers. Starlight Instruments manufactures different adapters for their 2.5" and 2.0" focuser models.
I am trying to eliminate image shift when focusing my AT106 with a heavy camera. Will this adapter help?
Absolutely. This adapter, when paired with a Feather Touch focuser, is a primary solution for eliminating image shift and flexure. By providing a solid, non-moving base for a high-quality rack-and-pinion focuser, it removes a major source of instability present in many stock focusers, ensuring your point of focus remains constant.
