Baader 1¼" filter holders for T-2 and 2" filter threads

1¼" filter holder for filter threads T-2 and 2

Time and again it happens that a 1.25" filter or other part (Barlow lenses, reducers) with a 1¼" filter thread has to be mounted in the light path of a larger telescope. This is the purpose of this filter holder, which consists of four components:

Baader T-2 Conversion Ring

Baader Double T 1¼" Filter Holder

T-2 1mm Fine Adjustment Ring (gold) - Aluminum

Baader T-2f / M48m Expanding Ring (T-2 part #29)

The Double T Filter Holder accepts common 1¼" filters as well as, for example, the Q-Barlow lens (note that this Barlow can only be screwed in about a quarter turn due to technical production characteristics).

When combined with the T-2 conversion ring, this results in a filter holder that can be screwed between any two T-2 parts and has a total length of 10 mm.
In combination with parts with 3 mm long T-2 threads, it seats flush; for parts with 5 mm long threads, a 1 mm T-2 fine adjustment ring (gold) is also included - Aluminum #2457913 so that all components seat flush with each other.
This allows 1.25" filters or Barlow/reducer lenses with standard 1¼" filter threads to be inserted permanently even in front of accessories that are screwed to the telescope via T-2 threads to prevent tilting, whether they are heavy eyepieces, cameras with filter wheels or an ADC.
By installing the filter holder facing one side or the other of the telescope, the distance of the filter/barlow to the camera/eyepiece can also be modified a bit.

With the T-2f / M48m expandable ring, the adapter can also be used on any 2" filter thread. Although this produces vignetting on long focal length wide angle eyepieces, it allows, for example, the use of a 1.25" filter (or Blaze grid) on 2" eyepieces or on cameras with a fixed 2" filter thread (and a small enough sensor) where the Baader 1¼" / T-2 plug-in connection with Kerfs safety # 2458106 or if a threaded connection to the telescope is preferred.