-----BEGIN PGP SIGNED MESSAGE-----
>>>>> "sh" == Stuart Heggie <stuart.j.heggie@sympatico.ca> writes:
sh> John, this is exactly what I needed to know - the dark red
sh> filter I have made an improvement for sure but it was much
sh> more subtle than I expected and not at all what I see when
sh> folks post "H-Alpha" shots. I guess it is Lumicon and step
sh> rings. Ah well, that is why I have a job, so I can pay for the
sh> more expensive solution when I have to. Thanks! Stuart
FWIW, my recent image of NGC7000/Gamma Cygni here
http://www.astrofoto.org/gallery/ngc/ngc7000.html
was shot with a Wratten 92 on E200 (extracting only the red channel).
I haven't worked out the TP thing to get it right.
Of course, the Wratten 92 is not really cheaper since you have to get
a filter holder, too....
roland
- --
PGP Key ID: 66 BC 3B CD
Roland B. Roberts, PhD RL Enterprises
roland@rlenter.com 6818 Madeline Court
roland@astrofoto.org Brooklyn, NY 11220
-----BEGIN PGP SIGNATURE-----
Version: 2.6.3ia
Charset: noconv
Comment: Processed by Mailcrypt 3.5.4, an Emacs/PGP interface
iQCVAwUBP5PclOoW38lmvDvNAQEIVAQAvVZw6paGuaD4SmspFGBy4qS+UUMHNUJv
By0RraXnRl4SOA5oQabGLFfbo9q+0I9VEa6uyaopgzbmxmViQxZBt//dOTcqUYjR
wlGFxqZPxoYnc4kDpT3O4Qk3bgeThMd4ljtK9rEkd3pQyBNLhJEWoj5B7cWV35A6
YmjYGv8/2XQ=
=8Qtb
-----END PGP SIGNATURE-----
_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo