I've always wanted a 5 Angstrom solar filter (or telescope) but could only afford the neutral density type in the past.
I'm seriously considering one now and have been searching for advice on this and thought someone here would have experience.
I've been looking at the Coronado Solarmax III. I like being able to add a second filter for a lower wavelength filter.
I also like that that model needs no electricity.
I have a Televue Oracle III (76mm) and an NP101is (101mm) and my inclination is to just get the filters for one of these instead of buying a dedicated scope.
What do you guys like?
I should be able to provide you with some feedback this weekend on the performance of a dual stacked dedicated solar scope (Pressure tuner in back, tilt tuner up front), vs a refractor using dual stacked tilt tuned etalons up front + blocking filter in the back.
Right now I'm running a Lunt 60mm f/8.3 LS60Tha Pressure Tune, for visual use only, with a 50mm double stack (LS50Fha) up front. With the stopped down aperture of the 50mm double stack up front, I believe that would make the system an f/10. Image is very pleasing, with many observable details, albeit I haven't been able to use too much magnification just yet; I would put my limited experience as an h-alpha observer and seeing conditions as being the predominant factor over the bottom line resolving power of the telescope.
I have a Televue 101 (TV-101) and will be trying a double stack of 50mm tilt tune etalons up front, and a B1800 blocking filter in the back. It should be a worthwhile comparison-- The TV's Petzval design has a doublet up front, with another doublet corrector in the back. The Lunt 60 pressure tuner has a singlet up front, with the internal pressure tuned etalon providing some kind of correction in the back. Different optical designs, but not too dissimilar. The TV101 with 50mm etalons up front would also be of a similar focal ratio at f/10.8...it should be an interesting and meaningful comparison.
I anticipate that with double stacked front etalons, the solar image might have some slightly perceptible banding, where the full disk may not be showing full detail like it would with the dedicated solar scope with pressure tuner. I don't think it will be a deal breaker, on the other hand. I like the versatility of using front etalons + blocking filter with other refractors. It limits the amount of gear to bring out. My hope is that using front etalons with the Televue refractor, with its good optics, will coax out some additional detail.
One thing with running front etalons + blocking filter + adapters on other refractors is that the whole system will wind up costing more than just buying a dedicated solar scope that is sold as a complete system.
Edited by Volvonium, 14 February 2020 - 12:57 PM.