What is the purpose of this Starlight Instruments 2.0" adapter?
This adapter is designed to allow you to mount a Starlight Instruments 2.0" Feather Touch focuser onto specific telescopes, such as the Orion 80 ED and 100 ED, that have a compatible optical tube inner diameter. It replaces the telescope's original focuser mounting system.
How do I confirm this adapter will fit my Orion 80 ED refractor?
While this adapter is listed as compatible with the Orion 80 ED, it is always best to measure your specific telescope. You must remove the stock focuser and measure the inner diameter of the optical tube where the focuser mounts. This adapter requires an inner diameter that accepts its 3.41-inch outer diameter for a snug fit.
What does the "No Thread" designation mean for this adapter?
"No Thread" means the adapter has a smooth barrel and is designed to slide into the optical tube, rather than screwing onto it. It is typically secured in place by set screws on the telescope tube itself, providing a firm, compression-based connection.
Which Starlight Instruments focuser should I use with this adapter?
This adapter is made to be paired with a Starlight Instruments 2.0" Feather Touch focuser, such as the FTF20 series (e.g., FTF2015BCR or FTF2020BCR). The focuser body will then attach to this tube adapter.
Will this Starlight Instruments adapter work with my Sky-Watcher Evostar 100ED?
The Orion 100 ED and Sky-Watcher Evostar 100ED are often mechanically identical, as both are manufactured by Synta. However, production runs can vary. To be certain, you must physically measure the inner diameter of your Evostar 100ED's tube to ensure it will accept the adapter's 3.41-inch outer diameter.
Why is the 4.0" length of this adapter important?
The 4.0" length is critical for placing the focuser at the correct distance from the objective lens. This ensures that you have enough focuser travel (in and out) to achieve sharp focus with a variety of accessories, from 1.25" eyepieces to large 2" diagonals and imaging cameras.
