Cosmic Impressions by Glenn Schaeffer

The Great Nebula in Orion (M42 & M43)

Orion Nebula


The Great Orion Nebula is the brightest nebula visible to the naked eye, forming the middle part of the Hunter's sword in the famous constellation Orion.  It is a breathtaking view in dark skies with my 20" Obsession where tendrils of gas can be appreciated.  This is my “second light” with my Canon 20D and scope setup.  I wanted to practice my imaging and processing techniques with an easy and bright target.  The objective of this shot was to observe different ISO settings and the amount of noise from each.  Because no flats or darks were taken and short shutter times, graininess was observed in the darker areas around corners of image.  This shot shows the approximate FOV that my camera/scope has at f/5.

Photographic Details:

Date & Location: September 20th  2006, Santa Fe, Texas.
Scope: Obsession 20” f/5 on a Tom Osypowski Dual Axis Equatorial Platform, Orion 100mm f/6 Guidescope.
Autoguider: SC1 Mod Celestron Neximage Cam,
Shoestring GPINT-PT guide port interface adapter, and Guidemaster software
Camera: Canon 20D DSLR (non-modded), homemade serial control shutter release cable and DSLR shutter from Stark Labs.
Filters: None
Conditions: Temp 48F, Humidity 51%, Winds Calm, Transparency 7/10, Seeing 6/10.
Exposures: 20 x 10sec @ 800 ISO, 18 x 10sec @ 1600 ISO, & 16 x 20sec @ 3200 ISO (no flats or darks)

Post-processing: 3504x2336 Raw files converted and resized 1200x800 (non-linear) using Canon’s Digital Photo Professional. Aligned, optimized, stacked, and stretched with Registax 3.  Slight use of Wavlet filtering in Registax as well as color balancing with the Histogram function. ISO 800 & 1600 used for core region. Final processing in Photoimpact SE.


Images Copyright 1999-2010 by Glenn Schaeffer