I am new to this forum, but have been dabbling in some solar observing and imaging for a couple years. I have a Quark Chromosphere that I am happy with. Daystar advices to use a UV/IR cut filter with scopes larger than 80 mm in aperture and also state that the UV/IR cut filter should not be used with oil spaced objectives.
The Lunt CaK module has a shiny filter/glass at the telescope side, but I have not been able to find out if that functions like a dichroic UV/IR cut filter and would make the module not suitable for oiled objectives. I could not find helpful information on the Lunt website and have called Lunt a few times without receiving a helpful answer.
While I have a air spaced telescope, my travel telescope has an oil-spaced triplet and I would love to be able to do some CaK viewing when traveling.
Thanks.
Lunt CaK module with oil spaced objectives
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Re: Lunt CaK module with oil spaced objectives
I have a TEC140 and have been using the Lunt CaK module with it with no problem. I must admit, I stop it down to 100mm when using it and I only use it for around a hour, I never leave it tracking on the Sun all day. But I guess you use it at your own risk (don't blame me). To be honest I think if I had a full front ERF on the front for the Lunt I might get better images (less heating inside) but I don't know of an ERF for CaK other than the Beloptik tri filter and you can't get hold of those.
With the Quark I have a full front Baader D-ERF to protect the objective.
Alexandra
With the Quark I have a full front Baader D-ERF to protect the objective.
Alexandra
Re: Lunt CaK module with oil spaced objectives
Thank you for sharing your experience. This makes me feel better. I am not sure that there is a ERF that lets CaK through. I have not been bale to find transmission data for the Lunt or Daystar ERF.
Ulrich
Ulrich
Re: Lunt CaK module with oil spaced objectives
I'm jumping in here late, but I had Omega Bob make me a full-aperture (95mm) CaK filter to rebuild my Coronado CaK 90 with. He can make thes in any size, and as wide or as narrow as you wish.
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- Omega full aperture CaK filter on Coronado 90 1 of 2.JPG (237.3 KiB) Viewed 3570 times