Re: Two Solstice Transits

Alan Friedman

Thanks very much Chris.

I’ve attached a photo of my case for the Stowaway which also carries my Ha solar gear. It’s remarkable compact. In here are the telescope and Coronado 90 etalon, 2” straight through blocking filter, mounting ring (standing in front but stows on top of the etalon at lower left), 1.25 mirror diagonal, zoom eyepiece, three streaming cameras + 1.25” nosepieces, Baader FFC, 2X Powermate, two extension tubes and cables to attach to various Mac computers. Phew!

The etalon screws to the tilting mechanism (black part) which is attached to an A-P traveler mounting ring. The latter was sold by Coronado at the time and for years I used the Coronado 90 on the traveler. The magical mating piece can be seen attached to the front of the Stowaway. It is a spare traveler tube ring purchased from A-P when I got the Stowaway. Its inside diameter is a perfect fit to the dew shield of the stowaway and the outside diameter is the same as the traveler dew shield, so the original mounting ring fits on it perfectly. The stowaway dew shield rotates which allows a subtle tilt change to the etalon - finer than the tilt achieved by the tilting mechanism. This rotation allows me to adjust the bandwidth with a good degree of precision and yields an evenly lit field of view across the entire disk of the sun at 900mm focal length. The 92mm aperture of the stowaway is a perfect match to the Coronado 90. A larger telescope could provide the same magnification without the use of the Powermate, but it would put the etalon much further away and make adjusting the bandwidth while viewing the result on a computer screen much more difficult. 

I’ve attached a photo of Ha stowaway (I call him Little Big Man) on my 1200 mount. There is a lovely 10” scope mounted in between in this photo but normally I have 6” tube rings on the mount and the Stowaway ride on a plate atop the 6” rings. 


On Jun 22, 2022, at 7:17 PM, Chris White <chris.white@...> wrote:

Wow!  Really amazing Alan!  Spectacular details on the disk and the ISS.  Soooo... coool.

How do you attach the coronado filter?  Do you have a picture of your setup?  I dabbled with solar with a lunt50 years ago, but the image circle was pretty small and the focal length was pretty short.  I've thought about doing it with my stowaway .  Thanks in advance!

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