Here is a recent image I made of NGC 1491. I used my C8 at f/5 - it is a slower narrow field for me then I normally use with my H-Alpha filter. Normally I try to shoot HA at f/2.8 to f/4 with 3-4 minute exposures. This image includes a 6 x 5 minute exposure - I really can't go too much longer than 5 minutes with my webcam.
I have attached an image, but a full size image as well as exposure and processing details are at:
http://jthommes.com/Astro/NGC1491.htm
Jim Thommes
http://jthommes.com/Astro/
I have attached an image, but a full size image as well as exposure and processing details are at:
http://jthommes.com/Astro/NGC1491.htm
Jim Thommes
http://jthommes.com/Astro/
Attached Image:
Jim Thommes
Mak-Newt 152 mm
C8
Megrez II APO
Zenithstar 66 mm APO
G11/Gemini
ST8300M
Artemis285 Camera
Canon 350D DSLR
http://jthommes.com/Astro/