Thank you for your help!
The 2" SC/HD-Clicklock has got a length of 47mm, our 2"-mirrors ca 112mm, our 2" prisms about 100mm (both including their clicklock eyepiece clamps) and our 1.25"-T-2-prism 64mm incl. eyepiece clamp. So, it is okay if you use a 1.25" star diagonal, but with a 2" star diagonal, the Alan Gee will be too far away from the eyepiece.
You can use the BTA (#21) and the Expanding Ring T-2f / M48m (T-2 part #29) #2458110 (optical length: 2.5mm) to attach the Clicklock to the BTA. But we'd recommend this only for 1.25" star diagonals.
The ASI has got a backfocus of 12.5mm from the T-2-thread, so you need ca. 108.5mm of distance.
If you attach the camera *directly to the BTA*, this can be achieved e.g. with
- 2x 40mm T-2-extension tube (T-2 part #25B) #1508153
- VariLock 46, lockable T-2 ExtensionTube 29-46mm (T-2 part #25V) #2956946
This will give you a length of 109mm, or if you want the more precise, you can use
- 1x 40mm tube
- 2x 15mm tubes (#1508154)
- 1x VariLock 46
to give you 99-116mm.
If you mount the Alan Gee in *front of the Clicklock*, you need e.g.:
- Expanding Ring T-2f / M48m (T-2 part #29) #2458110 - optical length: 2.5mm
- 2" SC-Clicklock - 47mm
- Baader 2" / T-2 Nose Piece (T-2 part #16) # 2408150 - optical length: 2.5mm
- 2 x 15mm T-2-extension tube (T-2 part #25A) # 1508154 - 30mm
- Baader VariLock 29, 20-29mm (T-2 part #25Y) # 2956929 - set to 26.5mm
- ASI cam - 12.5 mm
This will give you the desired working distance of 121mm.
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|Optical tube length||15|
|T-2 Part #||21|
|Usage||SC-T photo adapter|
|Inner Diameter / Clear Aperture (mm)||38|
|Inner Connection (lens sided)||Thread, T-2 (M42 x 0,75), 2"|
|Outer Connection (eyepiece/-camera-sided)||Thread, T-2 (M42 x 0,75)|
|Adaptable to||all male 2" SC-Gewinde from 5/6/8/11/14 OTAs|
|Compatible Brands||Astro T-2, Baader Planetarium, Celestron|
|Type of Adapter||Reducing piece|