comet Holmes 17/P shot with a 200mm/2.8 Canon lens working at f4. Camera was a SBIG STL11000. Exposure times were 3x600" for the blue filtered image and 3x300" for the red and green ones. Filters used were from Astronomik. During the green and red filtered images high altitude clouds were drifting through the field and produced halos around the brighter stars.
SBIG STL-11000,Canon 200mm/f2.8