CaK and filaments! 22 Nov 2021

[Merlin66]

The MiniSHG continues to show the filaments in CaK.
The DIY 1A filter on the 90/1000 Vixen still doesn't show them.....
The SHG image actually cleaned up pretty well this time. I added a 80a Blue filter I had available but the parasitic light is still there.
Enjoy!

[Eris]

Ken, congratulatuons on the excellent image set that you have posted.The filaments featured in the first image are really impressive.:thumbsup:

[Merlin66]

Gerard,
Yeah,
I'm finding the narrow bandwidth of the MiniSHG makes the difference.
The commercial CaK filters (around 2A) and the usual CaK double stack mod (around 1A) just don't cut it when trying to image filaments.
"The (filaments) appear ghostly, transparent, extremely faint" are some of the descriptions. Certainly not as well defined and contrasty as the SHG.

[Eris]

Yes, I agree Ken. On re-examination of your “broad band” image I can see with the help of my imagination a very faint wisp of one of the filaments – so easily overlooked. The narrow band of the MiniSHG certainly does make all the difference. You are on a winner there.