M57 - The Ring Nebula
From the author of Sizing Up The Universe
22:15 EDT June 26, 2008.
Starlight Express SXV-H9 on 10" RC at f/9.
Ha =140min, OIII=20min,
(guided 20 minute subexposures).
PLUS: all prior exposures.
Richardson-Lucy.
Brighter version
02:16 EDT May 23, 2007.
Starlight Express SXV-H9 on 10" RC at f/9.
L=32.5min, Ha =30min, OIII=30min,
R=15min, G=15min, B=15min (guided 2.5 and 5 minute subexposures).
Richardson-Lucy, Custom Digital Development.
02:43 EDT May 5, 2005.
Starlight Express SXV-H9 on 10" RC at f/9.
L=13min, Ha =22min,
R=8min, G=8min, B=8min (unguided 1-minute subexposures).
Richardson-Lucy, Curves.
NOTE: Comparison with http://c3po.cochise.cc.az.us/astro/images/M57!dss2_3.jpg reveals that the faintest stars in this image are at least mag 20.
23:07 EDT Aug 10, 2005.
Starlight Express SXV-H9 on 10" RC at f/9.
Ha =122min (unguided 30-second subexposures).
Richardson-Lucy, Gamma stretch.