"Tom" wrote in
:

I must admit, today is the first time I have ever looked at anything
with a decent scope. A store in Tucson AZ had an old AP refractor,
4 or 5 (or 6?) inches, aimed at the sun for customers. They used a TV
55mm plossl. Not a lot of magnification, but it was a joy looking at
the prominence.
I always figured that a prominence would move rapidly, but it just
stood there, suspended. She said it took like 8 minutes before you
can notice a change. Some people have said that solar observing can
be hazardous to your scopes health. They were doing it with an AP!!

I didn't take the time to find where the filter was located. Do you
think it
was the eyepiece, or on the top of the scope? Hmmm. -Tom

If you could see prominences, they were most likely doing it with a
Hydrogen Alpha filter like those from Coronado Filters
http://www.coronadofilters.com. This is a combination of an etalon
filter over the objective and a blocking filter at the eyepiece end.