I'm learning how to use my newly acquired Lunt CaK module (straight-through, B600). So far tried with my 90/660 mm Celestron achromat and with the GSO RC8 (with Aries ERF). Unfortunately there was literally nothing on the Sun at the time of capture, but the image quality seems promising (all from the 90 mm achro, PGR Chameleon 3 mono/ICX445, AviStack 2, ImPPG):
SW Barlow 2x:
- angle_0_b2x_stack.png (485.88 KiB) Viewed 671 times
PowerMate 2.5x:
- mos2_2.png (607.75 KiB) Viewed 671 times
(Seeing wasn't good enough for any useful results from the RC8.)
The good news is that in my case the PM 2.5x does not give any reflections like the ones described
here. There were some problems, though; in some configurations I was getting a distorted, "streaky" image:
- cak_09_pm25_bad.png (417.93 KiB) Viewed 671 times
Strangely enough, this was improved by just rotating the CaK module by 90 degrees (with camera, Barlow and telescope unchanged). I don't remember exactly, I might have also been moving the module up and down the drawtube (and compensating by moving the camera relative to the PowerMate). Perhaps differential heating (and distortion) of the module's front mini-ERF by a too-small input light cone? Definitely something to experiment with further.
My software:
Stackistry — an open-source cross-platform image stacker
ImPPG — stack post-processing and animation alignment
My images
SW Mak-Cass 127, ATM Hα scopes (
90 mm,
200 mm), Lunt LS50THa,
ATM SSM, ATM Newt 300/1500 mm, PGR Chameleon 3 mono (ICX445)
CaK is a tricky to get sorted at first, I'm still working on the C11 but the TEC140 seems to be good now 