What is the purpose of this Starlight Instruments 2.0" adapter?
This adapter's sole purpose is to securely mount a 2.0" Starlight Instruments Feather Touch focuser onto the large 3.29"-16TPI rear cell thread found on specific 11" and 14" Celestron SCTs. This allows you to bypass the telescope's native focuser, eliminating image shift and enabling more precise focus control for visual use and astrophotography.
Which Celestron telescopes are compatible with this 3.29"-16TPI adapter?
This adapter is designed for larger Celestron SCTs that use the 3.29"-16TPI thread specification. This includes the Celestron C11, C14, CPC1100, and NextStar 11 models. It is not compatible with smaller SCTs like the C8 or C9.25, which use a different thread size.
How does this adapter help with imaging Jupiter with my Celestron C14?
By enabling the installation of a Feather Touch focuser, this adapter eliminates the primary mirror "image shift" common with the stock focuser. This is critical for achieving perfect focus on Jupiter at high magnification without the planet jumping around in the field of view, which is a common frustration during planetary imaging.
How much length does this Starlight Instruments adapter add to my C11's optical train?
The adapter has a physical length of 0.45 inches. This is the amount of back focus it will consume in your imaging setup, so you should factor this into your overall optical train calculations.
Will this adapter work for attaching a Feather Touch focuser to my Celestron 8" SCT for imaging the Orion Nebula (M42)?
No. This adapter is specifically for the larger 3.29"-16TPI thread found on C11 and C14 models. A standard Celestron 8" SCT uses a smaller 2"-24TPI thread and requires a different adapter to mount a Feather Touch focuser.
Why should I use this threaded adapter instead of a standard visual back on my CPC1100?
This adapter provides a rigid, threaded connection for a high-precision external focuser. This is a significant upgrade over a standard slip-fit or compression ring visual back, especially for astrophotography, as it prevents any possibility of tilt or flexure in the imaging train that could lead to elongated stars at the edge of the field.
