Quote:
Originally Posted by Paddy
Hydrogen alpha enables you to see the textured details of the solar surface, prominences, filaments etc. They are expensive and the PST is the cheapest version probably. The virtue is that the sun is a great star to watch in hydrogen alpha as it always changes, even throughout the day. But you couldn't use the PST for any other observing. The bonus this year is that in addition to an eclipse, you get a transit of Venus on June 6th.
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Let's be VERY clear here...
Ha filters for solar observation are NOT the same for nighttime astronomical observing, so please be careful how you state or phrase what someone can and cannot use.
The specific Ha filter for solar observing is actually a Fabry-Perot style interferometer, also know as an Etalon. This specific equipment is used in conjunction with an Energy Rejection Filter and a Blocking filter to reduce the total amount of energy reaching the eyepiece and filters the the light by allowing only a small portion (less than one angstrom) of the overall spectrum through.
The statement that the PST is the cheapest version of "it" is almost correct in that it is the cheapest version of the *combination* of the three filters...
Please do not attempt to use a normal Hydrogen-alpha filter for solar observation, it will be the last time you see the sun...
OIC!
BTW: If you have any technical questions regarding solar observation, there are a couple of guru's on this forum, feel free to post questions, you will get a very good, solid answer.