Telescope: Skywatcher 8" f/5 Newtonian
Focus: Prime focus
Camera: SAC7B, uncooled
Exposure: Mosaic of 2 images 64 and 117 x 25s respectively
Date: 21st July 2003
Processing: The usual YRGB
processing, except that the subtraction of a 'banding flat' (see the
Advanced Processing page) was done to
remove fine banding noise in both the images in the mosaic. The left
component of the mosaic developed a broad banding pattern which I was unable
to remove completely. The residual can be seen in the final image.
This is probably the limit of my camera in
terms of recording faint nebulae. The right image had a large number
of frames and still only recorded the brighter parts. The left image
acquisition was cut short by cloud (hence the incomplete mosaic). As a
result there were not sufficient frames to subdue the banding. This
affected the technique I use to subtract a synthetic sky background and
resulted in a blue and green colour cast in part of the left image.
Overall though, an impressive number of stars were recorded!