Types of H-alpha filters

Started by [email protected], 01/10/2003 01:22PM
Posted 01/10/2003 01:22PM Opening Post
There are quite a few beautiful DSO images taken with H-alpha filtration these days. I'm unclear about the variety of such filters. I own, for example, a deep red filter called H-alpha which is intended for B&W photography; its function is to eliminate non-red components coming thru optical systems. Then there's the H-alpha used so well by solar imagers -- expensive but wonderful for a specific task.
It's the third category which I never heard of until the more recent posts that I'd like to know more about. For the exquisite DSO images we're seeing the band pass is apparently wider than those required for solar imaging and I assume, less expensive. Who makes them and for what price are they available? Are they a new development?
Any info appreciated.

Bob Polcyn
Posted 01/10/2003 05:30PM #1
Hi Bob,

Yes, there is another class of filters. They are very narrowband filters (3 to 15 nm) that can pass H-alpha, H-beta, OIII or several other important wavelengths. Check out this site for a nice discussion http://www.astrodon.com/EmissionFilters.html .

Enjoy!

Mike



Mike

http://www.DarkSights.com