RE: [Utah-astronomy] Urban astronomy
I have found the OIII to improve the contrast of the Veil, Planetaries and nebulas like Orion, the Eagle and Lagoon. I think that the OIII helps the Veil and the planetaries the most. Are these OIII emitters?Some of the nebulas become better with a UHC but I think that I like the OIII the best for most of the observing that I do. -----Original Message----- From: Chuck Hards [mailto:chuckhards@yahoo.com] Sent: Friday, March 14, 2003 1:27 PM To: utah-astronomy@mailman.xmission.com Subject: Re: [Utah-astronomy] Urban astronomy --- UTAHDEB@aol.com wrote:
I think an OIII filter is required for city observing
Do you mean required for the Veil, or city observing in general? An O-III filter will only improve objects that are emitting light at the O-III wavelength. C. __________________________________________________ Do you Yahoo!? Yahoo! Web Hosting - establish your business online http://webhosting.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Most, if not all planetaries emit at O-III, but I'm not sure about diffuse nebula; sounds like some of them do also from your experience. The O-III bandpass is very narrow, even compared to an UHC or other narrowband filter. Technically, the Veil is what's left of a planetary if you give it enough time, so the O-III should work with it. For city observing, I find the narrowband the most useful, a broadband works well at very high powers, when the sky background is naturally dimmed anyway. My O-III experience is from borrowed filters, I don't own one. C. --- David Dunn <david.dunn@albertsons.com> wrote:
I have found the OIII to improve the contrast of the Veil, Planetaries and nebulas like Orion, the Eagle and Lagoon. I think that the OIII helps the Veil and the planetaries the most. Are these OIII emitters?Some of the nebulas become better with a UHC but I think that I like the OIII the best for most of the observing that I do.
-----Original Message----- From: Chuck Hards [mailto:chuckhards@yahoo.com] Sent: Friday, March 14, 2003 1:27 PM To: utah-astronomy@mailman.xmission.com Subject: Re: [Utah-astronomy] Urban astronomy
--- UTAHDEB@aol.com wrote:
I think an OIII filter is required for city observing
Do you mean required for the Veil, or city observing in general? An O-III filter will only improve objects that are emitting light at the O-III wavelength.
C.
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participants (2)
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Chuck Hards -
David Dunn