Photo of the Week for August 8, 2014
Shawn Nielsen of Kitchener, Ontario, recently submitted this narrowband image of the Cygnus Wall, a section of the North American Nebula. Located near Deneb, in Cygnus the Swan, the nebula is impossible to see unless viewed under extremely dark skies. But with a specialized narrowband filter (a OIII type is best), even a small telescope operating at low power will bring it into view. Nielsen notes that Kitchener, with a metropolitan population of more than 500,000, is completely engulfed in light pollution, but thanks to narrowband filters, an entirely new world of astroimaging is available for those who live under adverse sky conditions.
This view contains three hours of hydrogen-alpha (Hα) images and two hours of OIII data. Nielsen captured the Hα frames last November using a modified Canon EOS Rebel T1i DSLR and the OIII data using an SBIG 8300M CCD camera. A Williams Optics ZenithStar apochromatic refractor equipped with an 0.8× focal reducer was used.