Image |
Click Thumbnail for full sized image. |
| Telescope |
Nikon 180mm F2.8 ED Lens at F2.8 |
| Mount |
Astrophysics 900 |
| Camera |
Class 1 NABG ST-8E, Second cooling stage enabled (all images
taken at -18C). |
| Camera Control Software |
MaximDL/CCD 2.03 beta |
| Location |
My light poluted yard in San Jose, California |
| Date |
September 27, 1999 |
| Sky Conditions |
Slightly above average transparency , moderate seeing. |
| Exposures |
5 minutes Red, 5 minutes Green, 10 minutes Blue,
all at 2x2 binning. I also did a set of full resolution (1x1 binning) luminance
images (6x10 minutes) but I didn't notice I was overexposing the core, not to
mention a few dozen stars! So, I used the Red exposure (after DDP) as the
Luminance because it had the best S/N. Because of this the resulting image is
half of what I was trying for.
I used standard RGB Gel filters in front of the camera lens. Not as elegant as
a color filter wheel but it alowed the lens to come into focus. I placed the
SBIG IR filter inline between the lens and the ST8E with a male-to-male
adapter.
|
| Image Resolution |
Images were taken at 765x510 (2x2 binning) |
| Processing |
All frames were corrected with bias, dark, and flat field
frames. I used heavy DDP (20%) on the luminance layer to bring out the core.
For final color balancing (it's still not perfect) I used Photoshop 5. |