Question about Lunt H-alpha Blocking Filter - B1200d2

[michael.h.f.wilkinson]

I might be able to get a second-hand Lunt 12mm blocking filter (diagonal type) with 2" nose-piece. Am I right in thinking that this nose-piece can be unscrewed and replaced by a 1.25"?

[MjrTom]

Hi Michael,

The Lunt blocking filter diagonals have a male T2 fitting so you would need a female T2 nosepiece which are a bit harder to find.

Mark

[michael.h.f.wilkinson]

Thanks Mark. As I have one on my B400, I should be OK (I doubt I could sell that separately). The 1200 should be fine for my planned mod (which may now have longer focal length

[brianb11213]

There are active components in the "nosepiece" of the Lunt diagonals so simply screwing off the 2" fitting T threaded "tube" and replacing it with a different one may not be a viable alternative.

Replacing the eyepiece well is not an issue.

[michael.h.f.wilkinson]

Thanks for the info. There aren't any active components in the B400, but then that might have to do with its size. I am awaiting a message from the seller on this point

[michael.h.f.wilkinson]

I did get the blocking filter, after getting confirmation from the seller the nose-piece held no optical components. I have swapped nose-pieces with the B400 of the LS35, and everything works fine. I even got 5 minutes of sunshine to test the configuration and the increase in the sweetspot is impressive. I can now get the entire surface and all proms properly illuminated (without any vignetting effects). Should make imaging (and later modding) a lot easier.

very happy with the new filter. Optics are pristine