40mm extension for 2" refractor focusers
The extension mounts between the telescope tube and the focuser and thus extends the telescope tube by 40mm.
40mm extension for refractor focuser
Refractors with 2" focusers are optimized for use with 2" star diagonals. Consequently, the focus is well behind the 2" sleeve. In direct view applications (astrophotography...), the focuser must be rotated far enough to achieve focus. Even 2" extension sleeves are often needed. .
The problem when the focuser is too far
♦ The mechanical rigidity decreases rapidly, the draw tube gets stuck and this leads to tilting
of the field of view and blurred stars on the edge.
♦ The lighting is worse because the long extension tube and the necessary extension sleeve cover the edge
The 40mm extension for the TS refractor focuser is the solution
The extension sleeve is not mounted behind the focuser but between the telescope tube and the focuser.
♦ The mechanical rigidity of the system is improved because the focuser can no longer be extended as far
I have to.
♦ Lighting is also improved because the sleeve has a large free passage.
The extension adjusts, among other things:
♦ Baader Steeltrack 2" refractor version
|- effective length:||40mm (without the male dovetail)|
|-- Inside diameter:||73mm. Fits all focusers with a male dovetail from 71 to 72.5mm diameter.|