Coronado

[Gomanson]

Last night at the Beginners' SIG star party I got a chance to see the sun for the first time. I saw it through the Tak and through the Coronado. I've seen a lot of ads for Coronado solar filters and special solar observer telescopes. All the scopes I've seen are over $1000 new. Apparently the standard cost of a solar filter is about $100. What's the advantage of the special Coronado telescopes, and why are they so expensive? Also, is there anywhere around that rents telescopes or filters? I just think it would be cool to have a few days with a "solar-enabled" telescope to show friends and family the brightest, most prominent, and yet least [directly] viewed object in the sky.

[youngsww]

I just think it would be cool to have a few days with a "solar-enabled" telescope to show friends and family the brightest, most prominent, and yet least [directly] viewed object in the sky.

Gomanson, that is exactly why you become a member of the MAS. You have access to both kinds for only $22.00 a year.

Which one were you last night? And why didn't you introduce yourself?

John

[ashutoshl]

What's the advantage of the special Coronado telescopes, and why are they so expensive?

The standard solar filters are supposed to reduce the intensity of the solar light so tha it is safe for viewing. In theory they are supposed to reduce the enrgy of all wavelenghts uniformly althoug this rarely is the case. The Sun that we "see" using a solar filter (in theory) should be similar to the one viewed with the naked eye except with a greatly reduced intensity.

Coronado scopes on the other hand allow only certain wavelengths of light (such as H- alpha) to pass thru and block all others. So you get to see the Sun at a specific wavelength using these scopes. The Sun will appear to be of a different color than the one using a standard solar filter. Also, you will see features (such as prominences, etc.) which will not be visible using a standard solar filter. Since they require special filters that allow only a specific (or a very narrow range of) wavelengths to pass they are expensive to fabricate.