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.
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.
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.