What is the primary function of the Baader UFC S70/T-2(F) adapter?
Its sole purpose is to connect the Baader Universal Filter Changer (UFC) system to a telescope or accessory that has a male T-2 (M42x0.75) thread. It acts as the bridge between your telescope's optical train and the main body of the filter changer.
Which side of the Baader UFC S70/T-2(F) adapter connects to the telescope?
The side with the internal female T-2 thread connects to the telescope, focuser, or flattener. The side with the external S70 dovetail connects to the Baader UFC base.
How would I use the Baader UFC S70/T-2(F) with a refractor and flattener?
Most field flatteners for refractors, such as those for a Sky-Watcher Esprit or William Optics GT series, terminate in a male T-2 thread set at a specific backfocus distance. You would thread this adapter directly onto the flattener, then attach the UFC base to the adapter's S70 dovetail. You must then ensure the rest of your imaging train (OAG, camera) meets the flattener's required backfocus distance.
Can I attach the Baader UFC S70/T-2(F) adapter directly to my ZWO ASI1600MM Pro?
No, this is a telescope-side adapter. The ZWO ASI1600MM Pro camera itself has a female T-2 thread, just like this adapter. You need a camera-side UFC adapter to connect the filter changer to your camera. This specific adapter is designed to go on the other end of the UFC, facing the telescope.
What is the S70 dovetail on the Baader UFC S70/T-2(F) adapter?
The S70 dovetail is Baader's proprietary large-format connection standard for the UFC system. It provides a secure, wide-diameter connection that prevents tilt and flexure, which is critical for maintaining a flat field in astrophotography. This adapter converts the common T-2 thread to this more robust S70 standard.
Does the Baader UFC S70/T-2(F) adapter add to my optical path length?
Yes, every adapter adds some optical path length. While the exact thickness is not specified, you must account for it when calculating your backfocus. The entire UFC system (base, filter slider, telescope adapter, camera adapter) has a specific total length that needs to be factored into your imaging train to achieve sharp focus, especially when using a reducer or flattener.