Hi all.

After geting strong advice from s.a.a not to risk the telscope and
eyepice on solar projection, I would like to check out solar filters
to be mounted in front of the telescope objective.

From what I understand, there are at least two types of filters.
The first is one that merely reduces the amount of light that enters
the telescope. The example pictures I have seen essentially show the
solar disc with some sun spots. Some people I have talked to, said
that these types of filters were very popular (in terms of sold units)
just before eclipses.

Now, we just had an eclipse a couple of months ago, and I don't know
when the next is to be expected. I have seen some mentioning of
"Hydrogen Alpha" filters, that only let specific parts of the hydrogen
spectrum through. There is some vague mentioning of these filters
being "expensive!", but, on the other hand, there may be way more detail
to be seen on the sun than with the more ordinary filters. The prospect
of watching the sun almost every day, to get an impression of the
dynamics of the sun, does have a stronger appeal to me than merely
having a quick look every eclipse or so.

All of this put the following questions to mind:

- What types of details can one expect to see with Hydrogen Alpha
filters that don't appear with the "ordinary" filters? I have the
impression protuberances and surface granularity would be visible.
What about flares? Other details? Would one see dynamic features
i.e. instant movement on the surface as opposed to sunspot positions
that change over hours and days?

The telescope in question is of 80 mm aperture with a 20-60x eyepiece.

- How much more expensive are the Hydrogen Alpha filters than ordinary
ones? 2 times? 10 times?

Any opinions much appreciated.

Rune