M20
To see
the faint detail in this image, adjust your monitor's brightness and contrast
to clearly show all 17 steps in this grayscale chart:
- Telescope:
Celestron C11 at f/6.5
- Zeiss
II German Equatorial Mount
- Santa
Barbara Instrument Group ST-8E NABG CCD camera (1530 x 1020 pixels, 9 x 9mm, monochromatic, 16 bit, 13.8 x 9.2mm array)
- CWF8
color filter wheel with IR-blocking clear, red, green, blue and
narrow-band (3nm) Ha dichroic filters
Exposure
Information
- Date:
Friday August 9, 2002
- Location:
Mt. Pinos, CA
- Elevation:
8300', OAT +50F
- Composition:
LRGB with L = R+B
- RGB
= 60:60:90 minutes. Total exposure time: 3.5 hours
- All
subexposures were 5 minutes each
- Plate
scale: 1.02 arc-sec/pixel
This very poor image of M20 suffers from soft
focus, coma, elongated stars, and severe chromatic aberration. It is placed
here as a reminder for me to shoot this beautiful emission & reflection
nebula again when I've resolved the problems with my C11 telescope, focal
reducer lens and camera system. I tried to patch-up this image in Photoshop,
but the injuries were severe and I couldn't do much for the patient.
So for now, just step back from your computer's
monitor about 20 feet, turn out the lights, and enjoy this object's splendid
colors!