365Astronomy Self-Centering 2" to M48 Adapter - M48 Extension Tube with 2-inch Nosepiece for 2" Focusers - 53mm Optical Length
The 365Astronomy Self-Centering 2" to M48 Adapter is a M48 Extension Tube with 2-inch Nosepiece that can be used to attach a large CDD or full frame dSLR camera to a 2" Focuser.
Bear in mind that it has got a 53mm optical length, although when we use the locking ring to push out the celf centering ring, this length would slightly increase, up to appr. 54.5mm.
Due to the design and purpose of this extension, it doesn't have a safety groove... It would just not make any sense, so this is not really a disadvantage.
This extension is available with a T-thread (M42x0.75) or M48 thread. This product listing is for the M48 threaded version.
HOW TO USE IT
Place the extension inside of the 2" barrel/drawtube of your focuser. Whilst holding the back end of the extension (the end with the T-thread or M48 thread), rotate the black recessed ring clockwise until it becomes stiff. Don't force it too much. It is normal that you might not be able to completely tighten it up, so you might feel that it is still a tiny bit loose, but it is good enough to achieve a coaxial alignment between the focuser and extension (thus the camera as well). The gap between the focuser's barrell (drawtube) and the extension's brass ring is very tiny, so you can now use the focuser's locking mechanism, i.e. a thumbscrew or thumbscrews. Best result can be achieved if the focuser's drawtube comes with a brass compression ring as well.
If you need to remove it, loosen up the focuser's thumbscrew(s) first and only then start unscrewing the black locking ring.
Please note, you don't need this special extension if you use a Primaluce Lab OnAxisLock as that works very similarly. It's just that the self centering mechanism is on the focuser's side.
- Male M48 mount to connect a camera
- Compatible with 2" focusers
- 53-54.5mm optical length
- 92mm full length
- Threaded to accept standard 2" filters with M48 thread
- High quality CNC machined accessory
- Black anodised finish inside and outside
- Matt black finish inside to reduce internal reflections
2" Extended M48 Adapter